The effectiveness of the vaccine after the first dose, according to Dr. William C. Gruber, senior vice president of Pfizer Vaccine Clinical Research and Development, at about 52 percent. After the second dose, this value increases to about 95 percent. “Two doses of the vaccine offer maximum protection,” he said.
Many experts have raised concerns that the coronavirus vaccines might protect some people better than others. However, the results in the educational materials indicate no such problem. The vaccine has a high rate of effectiveness in both men and women, and similar rates in whites, blacks, and Latinos. It also worked well on obese people who are at higher risk of developing Covid-19.
Some vaccines for other diseases produce a weak immune response in older adults. However, Pfizer and BioNTech found that people over 65 received about as much protection from the coronavirus vaccine as younger people.
“I was trembling while reading,” said Dr. Gregory Poland, a vaccine researcher at Mayo Clinic, and pointed to the robust response of vaccines in obese and the elderly. “This is a grand slam in every way.”
The road to a coronavirus vaccine ›
Answers to your vaccine questions
As the coronavirus vaccine nears U.S. approval, here are some questions you may be wondering about:
- If I live in the US, when can I get the vaccine? While the exact order of vaccine recipients may vary from state to state, most doctors and residents of long-term care facilities will come first. If you want to understand how this decision is made, this article will help.
- When can I get back to normal life after the vaccination? Life will only get back to normal once society as a whole receives adequate protection against the coronavirus. Once countries have approved a vaccine, they can only vaccinate a few percent of their citizens in the first few months. The unvaccinated majority remain susceptible to infection. A growing number of coronavirus vaccines show robust protection against disease. However, it is also possible that people spread the virus without knowing they are infected because they have mild symptoms or no symptoms at all. Scientists don’t yet know whether the vaccines will also block the transmission of the coronavirus. Even vaccinated people have to wear masks for the time being, avoid the crowds indoors and so on. Once enough people are vaccinated, it becomes very difficult for the coronavirus to find people at risk to become infected. Depending on how quickly we as a society achieve this goal, life could approach a normal state in autumn 2021.
- Do I still have to wear a mask after the vaccination? Yeah, but not forever. The two vaccines that may be approved this month clearly protect people from contracting Covid-19. However, the clinical trials that produced these results were not designed to determine whether vaccinated people could still spread the coronavirus without developing symptoms. That remains a possibility. We know that people who are naturally infected with the coronavirus can spread it without experiencing a cough or other symptoms. Researchers will study this question intensively when the vaccines are introduced. In the meantime, self-vaccinated people need to think of themselves as potential spreaders.
- Will it hurt What are the side effects? The vaccine against Pfizer and BioNTech, like other typical vaccines, is delivered as a shot in the arm. The injection is no different from the ones you received before. Tens of thousands of people have already received the vaccines, and none of them have reported serious health problems. However, some of them have experienced short-lived symptoms, including pain and flu-like symptoms that usually last a day. It is possible that people will have to plan to take a day off or go to school after the second shot. While these experiences are not pleasant, they are a good sign: they are the result of your own immune system’s encounter with the vaccine and a strong response that ensures lasting immunity.
- Will mRNA vaccines change my genes? No. Moderna and Pfizer vaccines use a genetic molecule to boost the immune system. This molecule, known as mRNA, is eventually destroyed by the body. The mRNA is packaged in an oily bubble that can fuse with a cell, allowing the molecule to slide inside. The cell uses the mRNA to make proteins from the coronavirus that can stimulate the immune system. At any given moment, each of our cells can contain hundreds of thousands of mRNA molecules that they produce to make their own proteins. As soon as these proteins are made, our cells use special enzymes to break down the mRNA. The mRNA molecules that our cells make can only survive a few minutes. The mRNA in vaccines is engineered to withstand the cell’s enzymes a little longer, so the cells can make extra viral proteins and trigger a stronger immune response. However, the mRNA can hold for a few days at most before it is destroyed.
Even if the vaccine is approved by the FDA, the study will continue. In the briefing documents, the companies said they would encourage people to stay in the study for as long as possible without knowing whether they received the vaccine or the placebo, so the researchers can continue to gather information on whether the vaccine is safe and effective.
The educational materials also provide a deeper look into the safety of the vaccine. In any large clinical trial, some people who receive vaccines have health conditions unrelated to the vaccine itself. Comparing their symptom rates with those of the placebo group, as well as background rates in a population, may indicate symptoms that a vaccine may actually cause.
The FDA concluded that there were no “significant imbalances” between the two groups in serious health complications known as adverse events. The agency found that four people in the vaccinated group had a form of facial paralysis called Bell’s palsy, with no cases in the placebo group. The difference between the two groups was not significant and the rate in the vaccinated group was not significantly higher than in the general population.