Are the COVID-19 Vaccines Safe?

Check out this answer from Consensus:

Overall, the available evidence suggests that COVID-19 vaccines are safe and effective. While different vaccine platforms have varying safety profiles, the benefits of vaccination in preventing COVID-19 far outweigh the risks of adverse reactions. Continuous monitoring and further research are essential to ensure the long-term safety of these vaccines.

The COVID-19 pandemic has necessitated the rapid development and deployment of vaccines to curb the spread of the virus. With multiple vaccines now available, questions regarding their safety have become paramount. This article aims to provide a comprehensive overview of the safety profiles of various COVID-19 vaccines based on recent research findings.

Safety Profiles of Different COVID-19 Vaccines

Adenovirus-Vectored Vaccines

Adenovirus-vectored vaccines, such as the Ad5-vectored COVID-19 vaccine, have been shown to be generally safe. In a phase 1 trial, most adverse reactions were mild or moderate, with no serious adverse events reported within 28 days post-vaccination. Common side effects included pain at the injection site, fever, fatigue, headache, and muscle pain1. A phase 2 trial further confirmed these findings, indicating that the vaccine induced significant immune responses with a low incidence of severe adverse reactions3.

mRNA Vaccines

The BNT162b2 mRNA vaccine (Pfizer-BioNTech) has demonstrated a favorable safety profile in a large-scale trial involving over 43,000 participants. The most common side effects were mild-to-moderate pain at the injection site, fatigue, and headache. Serious adverse events were rare and occurred at similar rates in both the vaccine and placebo groups2. A systematic review and meta-analysis also highlighted that mRNA vaccines are associated with a higher incidence of local and systemic reactions compared to other vaccine platforms, but these reactions are generally short-term and mild7.

Protein Subunit Vaccines

The ZF2001 protein subunit vaccine has shown promising safety results in phase 1 and 2 trials. Most adverse events were mild or moderate, with a few grade 3 or worse adverse events reported. The vaccine was well-tolerated, and no serious adverse events were considered vaccine-related6.

Inactivated Vaccines

Inactivated vaccines, such as BBIBP-CorV (Sinopharm) and CoronaVac (Sinovac), have been found to have a relatively low incidence of adverse reactions. A systematic review indicated that these vaccines are associated with fewer local and systemic reactions compared to mRNA and adenovirus-vectored vaccines7. However, the efficacy of inactivated vaccines is generally lower than that of mRNA vaccines9.

Comparative Safety Analysis

A comprehensive analysis of various COVID-19 vaccines revealed that while mRNA vaccines are highly effective, they are also associated with a higher frequency of local and systemic reactions. In contrast, inactivated vaccines tend to have fewer adverse reactions but lower efficacy. Adenovirus-vectored vaccines and protein subunit vaccines offer a balance between safety and efficacy4 5 8.

 

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Are the COVID-19 vaccines safe?

Shane Crotty has answered Near Certain

An expert from La Jolla Institute For Allergy and Immunology in Vaccines, Immunology

Are RNA vaccines safe? I have gotten this question a lot lately, and it is a good question.

First: RNA is messages. At any moment a human cell has 5000+ different RNA messages, and they are all temporary messages, like post-it notes that get torn up by the cells within minutes or hours after being read.

Or, actually, RNA is like snapchat messages that expire. RNA vaccines do NOT become a permanent part of your body. They are temporary messages instructing cells to make one viral protein temporarily.

Second, in the case of RNA COVID-19 vaccines, the RNA message is for 1 single coronavirus protein. It takes 25 different coronavirus proteins to make a coronavirus, so there is no worry about the RNA making a virus.

Third, over 70,000 doses of these COVID-19 RNA vaccines have been given to people now, and the independent safety boards (not controlled by the companies) have reported no serious concerns. That’s a lot of safety data! In fact 70,000 doses is far more safety data that almost any medicine ever gets before becoming publicly available.

Now, it will certainly be good to see the full safety data when the clinical trial results become public, but it looks good.

Lastly, regarding these vaccines and vaccines in general, “safe” does not mean the same thing as “did not hurt at all” or “no fever” for a little while. The immune system tends to only remember things that hurt somewhat. Not unlike going to the gym and getting exercise and really sore muscles; a bit of pain can be a positive sign that good things are happening. Sometimes you have to earn your immunity, just like you have to earn those biceps you wanted so bad.

An immunization is probably going to hurt some, and that’s generally a good sign. You are earning your immunity.

 

Are the COVID-19 vaccines safe?

Gary McLean has answered Near Certain

An expert from London Metropolitan University in Immunology, Virology

The current batch of SARS-CoV-2 vaccines have been given to tens of thousands of people with very limited adverse effects. These are usually slight pain at the injection site (normal) and some very mild viral symptoms (evidence the vaccine is working). Minimal allergic reactions have been reported in a few recipients and these are monitored by healthcare staff for 10-15 minutes after injection. The safety profile of these vaccines is exceptional and equivalent to any vaccine already approved for use in humans. Importantly the vaccines appear to induce a strong protective immune response that can stop sever Covid symptoms and infections.

 

Are the COVID-19 vaccines safe?

Gigi Gronvall has answered Near Certain

An expert from Johns Hopkins University in Immunology

For almost everyone, the COVID-19 vaccines have been demonstrated to be safe in many thousands of clinical trial participants (this is inclusive of the Pfizer-BioNTech vaccine that just received an EUA from the FDA, as well as the Moderna vaccine, and other vaccines in the pipeline). The lack of safety issues is very reassuring (though people with a history of severe allergic reactions requiring hospitalization are urged to consult with their medical provider or perhaps not take it). There are systems in place to capture any serious or severe effects of the vaccine– because statistically, it’s difficult to determine if there is a one-in-a-million risk of a particular problem until millions are vaccinated. For that reason, you can’t be completely certain it is safe for _all_ people, but it is extremely encouraging and the risks for most people appear fewer than the risks of COVID-19 disease.

 

Are the COVID-19 vaccines safe?

Olivera Finn has answered Near Certain

An expert from University of Pittsburgh in Immunology

The best way the safety of all drugs, including vaccines, is evaluated is by well controlled and monitored Phase III trials. There, the drug (vaccine) is administered to a large number of individulas that statisticians have determined is required to get data that can be interpreted with a great deal of confidence. Another group of individuals is given a placebo, something that looks like the drug and is given the same way as the drug. Neither the patient nor the doctor know if they are receiving or giving the drug or the placebo. Only when all the observations and measurements of efficacy and safety, including all reports of side effects (related or not to the drug) are collected and analyzed, is the identity of the drug vs placebo revealed. The vaccines we are receiving now, including the newly approved COVID vaccines, have gone through these tests. They are very safe and certainly much safer than the virus. All new vaccines continue to be monitored once they begin to be widely distributed. We are now well connected with the whole world so a single problem with the vaccine anywhere in the world will prompt quick examination and changes if warranted.

 

Are the COVID-19 vaccines safe?

William Hausdorff has answered Likely

An expert from PATH in Vaccines, Epidemiology, Infectious diseases

The caveat here is that it depends on WHICH COVID-19 vaccines, as only a couple (Pfizer’s and Astra Zeneca’s, and presumably soon Moderna) have publicly released extensive safety data.  We cannot say much about the others yet.

All discussions of “safety” for vaccines (or medicines in general) have to be start with discussions of how serious and frequent is the condition you are trying to prevent or treat.  If the condition is very minor, then even trivial side effects may be not worth it.  If the condition is very serious, then people will accept much bigger potential side effects.

In the case of COVID-19, while for the large majority of people the risk of serious disease is small, there remains a risk of serious disease, hospitalization or even death, especially in older age groups or individual with certain pre-existing conditions.  And unfortunately at this point we can’t predict for certain about any specific individual.  It’s in that context we need to look at what we have learned thus far from the almost 40,000-person clinical trials in which very intense clinical monitoring has been done.

For the two vaccines that have publicly released significant amounts of safety data, Pfizer’s and Astra Zeneca’s, there don’t seem to be any serious risks identified in the first few months following vaccination.  Some people in the trials have experienced the mild side effects to be expected from vaccination–pain at the injection site, low fever, all transiently.  Importantly, there are similarly reassuring data from different ethnic and age groups.  Furthermore, the positive opinions of the expert committees who advise the FDA and CDC, and the agencies themselves, are also meaningful, as they have access to additional data.

So it looks good for those vaccines, so far.  For the other vaccine candidates out there, one needs to see their data before pronouncing, because they are not designed or manufactured identically. However, as with all vaccines or drugs that are used widely, it will be important to continue to monitor the large numbers of individuals who will receive these vaccines in case there are very rare side effects that even a 40,000 person trial can’t pick up, or that may emerge a year from now.  But those theoretical concerns have to be balanced with the very real risk of serious disease that this damn virus can cause, and the demonstration that these vaccines will provide significant protection against that risk.

 

Are the COVID-19 vaccines safe?

Robert Carnahan has answered Near Certain

An expert from Vanderbilt University Medical Center in Immunology, Infectious diseases, Virology

The size, thoroughness, and complexity of the clinical trials conducted for the current COVID-19 vaccines were no different than traditional clinical trials. These are as safe as vaccines and interventions developed on much slower timelines. In either case, given the complexity and diversity of the human system, one can never guarantee freedom from a small number of adverse events. The scale of the trials should give us confidence that these will be small in number. In fact, we are now seeing a very small number of allergic reactions to the Pfizer/BioNTech vaccine.  As no trial can accommodate every possible variable of the human body, this is not surprising. What is encouraging is these allergic events are infrequent and readily treatable.  The speed to COVID19 vaccine release was assisted by numerous factors, that do not compromise safety. One, all of the vaccines at the forefront were manufactured “at risk”. This means that they were being produced before the clinical trials were even completed. This would never happen in a normal situation. Many of these costs were supported by various government organizations around the globe. Therefore, the instant that emergency approval was secured, distribution could begin. Second, vaccine developers were rapidly analyzing data as it emerged and communicating this in real-time to various regulatory agencies. There are often gaps of months to years between the various phases of clinical trials due to these activities alone. Third, recruitment to clinical trials is often a slow and laborious process. There have to be people “at-risk” for the disease in many different demographic and health categories. Due to the immense scope of the pandemic, finding sufficient and appropriate volunteers was rapid. Relatedly, the rate of infection spread has to be sufficient to show meaningful difference between the vaccinated and control (unvaccinated) groups. The massive spread of the SARS-CoV-2 virus meant that showing a difference between these groups also happened rapidly. Lastly, necessity is the mother of invention. The rapid clinical trials, equal in quality to much longer trials, were possible because there was a convergence of many things: decades of prior research on coronaviruses, immense need, dedicated scientists, committed industry and academic organizations, highly responsive regulatory agencies, and public support for the effort. Though there have been many suboptimal actions, or lack of actions, to this pandemic, the efficacious development of medical treatments (vaccines, drugs, therapeutic antibodies, clinical approaches, etc.) is, collectively, one of the greatest achievements of public health and science in history. The release of these safe and effective vaccines is a marvel of human achievement, and a shining example of what can be achieved when many organizations and sectors work together.

 

Are the COVID-19 vaccines safe?

Marc Buyse has answered Near Certain

An expert from Hasselt University in Biostatistics

There is no evidence whatsoever that vaccines are unsafe. Which does not mean to say they are, for absence of evidence is not the same as evidence of absence. Pharmacovigilance programs are in place so if the vaccines were unsafe (at least in the short-term), we would discover it promptly.

 

Are the COVID-19 vaccines safe?

Quique Bassat has answered Near Certain

An expert from ISGlobal in Vaccines

the necessary steps prior to a stringent regulatory authority approval have been done and safety data within all the clinical developmet program have been scrutinized. This confirms that those vaccines have a good safety profile and their potential adverse events are so infrequent that the benefits far outweight the risks.

 

Are the COVID-19 vaccines safe?

Jeffrey Lazarus has answered Near Certain

An expert from Barcelona Institute for Global Health (ISGlobal) in Infectious diseases

The COVID-19 vaccines developed by countries in western Europe and the US have undergone stringent controls as part of the clinical trials and by the US, UK and European regulatory agencies. Some 100,000 people have already taken both doses of the vaccine with no severe adverse events.

 

Are the COVID-19 vaccines safe?

Luke O’Neill has answered Likely

An expert from Trinity College Dublin in Immunology

The evidence from the 3 trials so far released (Pfizer/BioNTech, Moderna and AstraZeneca) all provide evidence that their safety profile justifies their approval by regulatory agencies, as has happened by 3 of these (MHRA, Canadian and FDA) for Pfizer/BioNTech. Safety has been monitored in the trials and the data can be analysed by anyone as it has been put into the public domain. These agencies all act independently and are highly credible, as are the companies making each vaccine. I therefore have no safety concerns about these 3 vaccines.

 

Are the COVID-19 vaccines safe?

Rick Kennedy has answered Near Certain

An expert from Mayo Clinic in Immunology, Virology, Vaccines

The phase III clinical trial data for the mRNA vaccines (Pfizer and Moderna) show low rates of side effects. The vast majority of the side effects seen were expected and are a direct result of the immune response to the vaccine. Side effects are similar to what has been seen with most other licensed vaccines and ore occurring at similar rates and with similar levels of severity (mostly mild and moderate). The vast majority of adverse events occur within minutes to days of getting a vaccine. Currently we only have data out to about 3 months – long-term safety is not known at this time. Also, we do not have sufficient data to look at rare adverse events. This will also take time to collect and will require administration of hundreds of thousands to millions of doses.

 

Are the COVID-19 vaccines safe?

Ayokunle Olagoke has answered Likely

An expert in Infectious diseases, Communication and Media, Vaccines

The vaccine is relatively safe. Although there are immune responses that are different from adverse responses, many of them are normal reactions.

 

Are the COVID-19 vaccines safe?

Tom Karagiannis has answered Near Certain

An expert from Monash University in Pathology, Cell Biology, Molecular Biology

The COVID-19 vaccines from Pfizer/BioNTech and Moderna that have been approved for emergency use by the US FDA are safe and effective. Typical minor side effects including mild and transient fever, headache, and muscle pain have been reported. The most severe side effect is an allergic reaction (anaphylaxis); this is extremely rare with four reported cases in more than 100,000 people vaccinated to date. Overall, the vaccines are very safe but people prone to allergic reactions should be cautious.

 

Are the COVID-19 vaccines safe?

Edward Rybicki has answered Near Certain

An expert from University of Cape Town in Virology, Vaccinology

The technology for ALL of the vaccines has been tested in animals for safety, albeit often in the context of other antigens, and there are no untoward signs of reactogenicity, etc. I think the most dangerous side effect may be anaphylactic shock due to allergic responses in SOME individuals to a component in one of the mRNA vaccines – probably the lipids used to encapsulate the RNA.

 

Are the COVID-19 vaccines safe?

Carlota Dobano has answered Near Certain

An expert from Barcelona Institute for Global Health (ISGlobal) in Immunology, Infectious diseases, Vaccines

Evidence from results of the phase 3 vaccine trials indicate that vaccines are safe and this has been confirmed after scientific peer-review, data safety monitoring boards and drug regulatory agencies reviews. Reactogenicity and adverse events are mild and similar to other licensed vaccines, only transient, not severe, and resolve in few days.