Are the Covid-19 vaccines not safe because they were created so quickly?

(Tiếng Việt)

Claim: Many Vietnamese Americans believe that the development of the Pfizer and Moderna COVID-19 vaccines were rushed and are therefore, not safe. 

Rating: This claim is FALSE. Developing and testing a new vaccine usually takes years. But the COVID-19 vaccines, from manufacturers Pfizer and Moderna, took only 10 months to develop. That is because it’s a new type of vaccine made from messenger RNA (mRNA). It does not contain any live viruses, which makes it faster to develop. Research into mRNA vaccines have been ongoing since 1976, so the COVID-19 vaccines were the results of many years of research.


mRNA is found in all living cells. mRNA is the intermediate between DNA and proteins, and encodes the sequence for a specific protein. 

The mRNA vaccines are a new type of vaccine, but the research into mRNA has been ongoing since 1976. Scientists discovered that instead of growing a weaker version of the virus in cells and then putting them into vaccine vials, it was faster to create a mRNA that could tell human cells to produce a specific viral protein. Those viral proteins are then recognized by our bodies as foreign, which then produces the antibodies to fight it. 

An mRNA vaccine basically allowed scientists to use fewer and less time intensive steps during vaccine development, which is why it’s faster to develop.

By using mRNA, vaccines can be rapidly generated. Once the COVID-19 viral sequence was revealed to scientists in January 2020, development of mRNA vaccine candidates began. Scientists were basically given a blueprint for how to create COVID-19 proteins. They chose one COVID-19 protein, called the spike protein. They then put an mRNA that can create that spike protein into the vaccine. With only one protein being made, absolutely no infectious virus can be produced, but our immune system can create potent antibodies which can neutralize the virus if you are exposed.

Vaccines go through three stages of development, according to the U.S. Center for Disease Control. In each phase, the vaccine is given to more and more people to test. The Pfizer vaccine was tested on 43,661 people and the Moderna vaccine was tested on 30,000 people. The most severe side effect reported was fatigue.

Once the three stages are complete, the vaccine must go through a multi-step approval process from the Food and Drug Administration (FDA). Even after approval of a vaccine, the FDA still monitors the vaccine and the production activities. 

Both the Pfizer and Moderna vaccine applied and were approved for an Emergency Use Authorization (EUA). In order to submit for an EUA, these vaccines needed to be at least 50% effective, and both mRNA vaccines exceeded this threshold. The FDA determined that the known and potential benefits of both the Pfizer and Moderna vaccines outweighed the known and potential risks

The committee that grants an EUA for a vaccine is composed of impartial physicians and scientists that are globally recognized experts in the complexity of vaccine development, and in evaluating the safety and effectiveness of all vaccines. 

Pfizer COVID-19 vaccine: 

Moderna COVID-19 vaccine: 

As of February 4th, Johnson & Johnson submitted their vaccine for an EUA from the FDA. Unlike the Moderna and Pfizer vaccines, the Johnson & Johnson vaccine only requires a single dose, which has a 66% overall efficacy rate. Our team is keeping a close eye on the news as more information comes out on the Johnson & Johnson vaccine. 

The Pfizer and Moderna vaccines are safe and have gone through rigorous testing before gaining approval from the FDA. But for additional safety, wearing a mask (or two), avoiding indoor social gatherings, and staying at least six feet away from people not in your household is still recommended after you have been vaccinated.