Six Important Questions About Booster Shots Answered

The three Covid-19 vaccines that were approved in the U.S. last winter proved to be more successful than anyone could have imagined. Anthony Fauci, the director of National Institute of Allergy and Infectious Diseases said last year that a vaccine with 50-60 percent effectiveness would suffice. FDA would approve any vaccine with greater than 50% efficacy. Clinical trials proved that Moderna and Pfizer vaccines were 95 percent safe against symptomatic infections and almost 100 percent effective against hospitalizations and deaths. Johnson and Johnson's single-dose vaccine was slightly less effective at 67 percent, but it was still 100 percent effective against hospitalization and deaths.
Many scientists worry that this powerful immunity could diminish over time. It wasn't known how long the vaccines would protect because they were approved after the trials had been completed. Scientists pointed out that certain vaccines like the influenza vaccine, are only required once a year, while others provide lifetime protection. They also wondered what category Covid shots would be placed in. Although no one can say for certain when or if additional shots would be needed, Pfizer asked regulators to approve a third shot. However, this was just a few weeks after Pfizer had planned to ask them.

The FDA announced on August 12 that patients with compromised immune systems would have access to third doses Pfizer and Modernas vaccinations. The CDC provided detailed recommendations on who would be eligible a few days later. A few days later, the Biden administration made clear that all people will eventually require booster shots and that they could be available for purchase as soon as September.

Kartik Cherabuddi, who treats complex infections like HIV at the University of Florida says that he has seen an increase in the number of immunocompromised patients admitted into the hospital using Covid-19 since July. This is why it's important to consider the third dose for immunocompromised patients. We are starting to see them admitted to the hospital.

Soumya Swaminathan, the chief scientist at World Health Organization (WHO), suggested that booster shots should be prioritized in wealthy countries such as the U.S., but other scientists are still arguing that it is too early. There has been some confusion caused by the avalanche of new information. These are the most important questions.

Who and when will you need a third shot?

The CDC has limited numbers of people who are moderately to severely immunocompromised and will be the first to receive the third shot. These individuals are eligible for the third shot today.

The Biden administration plans to offer shots for the rest of the population who are gradually losing the effectiveness of the vaccine. It will start with those who were vaccinated first during the original vaccine rollout, and continue onwards with people over 65 years old. Eight months after your second shot, you will be eligible for the third. This means that aside from immunocompromised patients, the rollout will look very similar to the previous one. To review the evidence and make recommendations, the FDA must authorize the plan.

Onisis Stefas is the chief pharmacy officer at Northwell Health, New York City. He says that immunocompromised patients go first because they are not losing their immunitymany never had a strong immune system to begin with. Immunocompromised patients have a lower chance of being able to fight off infections like the coronavirus. This means that if you get infected you will likely be more severely than someone with a healthy immune system.

In spring 2011, studies showed that patients who had received solid organ transplants and certain cancer treatments were less likely to produce antibodies after vaccinations than those who were healthier. This suggests that they are not protected from diseases. A small study found that 44 percent of patients who are admitted to hospital for breakthrough treatment were immunocompromised. The study, which was done before the Delta variant became dominant, found that vaccine was only 60 percent effective in immunocompromised subjects.

Stefas says that many patients who are immunocompromised have not received full coverage with the two-dose regimen.

One trial found that solid organ transplant patients who had received Modernas vaccine twice in the past showed significant increases in their antibody levels. This suggests that they were more protected from the disease. These patients were therefore placed at the forefront of the booster line.

There are many conditions that can affect your immune system. However, the CDC recommends third shots for patients who have been treated for cancer or other diseases, are currently receiving treatment for them, or are taking high dose corticosteroids.

Two main findings led to the August 18 announcement that all will require a third shot. First, the immunity acquired from vaccines appears to diminish over time. The data from Israel, the country that was the first to give the Pfizer vaccine to its majority of population, shows that over half of all infections occur in those who have been vaccinated. Preprints suggest that people who have not had their second shot in a while are more likely to get a breakthrough infection. Data from the CDC showed that infection immunity has been declining in the U.S., although most people in both countries are still protected against severe illness and hospitalization.

The second important finding is that, while vaccines protect most patients against hospitalization and death due to illness, the new Delta variant can infect those who have been vaccinated. These individuals are more likely to spread the disease to others than those who have not been vaccinated. However, it is less common.

What does a third shot do to build immunity?

The body has many weapons that can fight infection. Your immune system recognizes a new intruder like SarsCoV-2, which causes Covid-19. It mobilizes an all out attack and produces unique immune cells to kill it. However, this can take time, and often the disease causes severe damage before your immune systems are able to respond.

Your immune system is introduced to Sars-CoV-2 protein with your first vaccine. Your cells recognise that the protein is not part of your body and build an army to combat it. That army includes antibodies which are specifically-tailored to neutralize that protein, and B and T cells which work together to produce said antibodies. Your body might stop producing new antibodies if you don't see the virus for a while.

These cells are kept in hiding, and when exposed to the virus, they will actually come out and perform their function and produce more antibody, according Catherine Liu, a vaccine researcher at Fred Hutchinson Cancer Research Center. Those antibodies can help protect you.

Your B and T cells can recognize the protein, and mount an immune response faster. This allows you to quickly produce neutralizing antibodies and eliminate the invader from your body with a second dose. The third dose is similar. It reminds your immune system of the virus's appearance so that it can mount an immune response in the event that it ever comes into contact with it.

Stefas says that the third dose provides additional support to your body in order to continue to mount an immune response. Your body will be able to fight off the coronavirus if it does come into contact.

Are there any potential risks?

The safety data for a third shot is the same as the first and second shots. The injection site pain was very common. Some people experienced fevers, headaches and muscle pain for up to two weeks. Seventy-nine percent of the one million Johnson & Johnson vaccine recipients were 18-49 years old. The shot caused dangerous and abnormal blood clots. Rarely are there any severe side effects such as blood clots and anaphylactic reactions. FDA has not yet reviewed safety and efficacy data for third shots for healthy individuals.

More than a million people are believed to have received third shots in the U.S., as well as in Israel. There have been no safety concerns.

Experts recommend that patients with immunocompromised should discuss vaccines with their doctors. First, immunosuppressants can cause unwanted effects if you are injected with the vaccine. Peter Gulick, an infectious diseases specialist at Michigan State University, says that stimulating your immune system to react to Covid-19 may cause it to attack a transplanted body. Liu states that although this possibility exists, it has not been proven in any of the studies that have been done on transplant patients. However, she says that people will be looking for similar results.

Your physician may recommend that you stop or decrease the immunosuppressant therapy before receiving the vaccine. This will give your immune system the best chance of building a strong response.

Do I have to get the same shot as before?

The CDC recommends that you keep the same shot as you received. Your third dose should also be from Pfizer if your first two doses were from Pfizer. Although some studies compared the AstraZeneca and Pfizer vaccines, the researchers have not fully investigated how Moderna, Johnson & Johnsons vaccines could work together.

All vaccines have been authorized by the FDA under an emergency authorization. The FDA has approved a third dose Pfizer and Moderna for immunocompromised patients. It is expected that the agency will soon authorize third doses of all vaccines for everyone in the coming days.

What if I had the Johnson & Johnson shot instead?

FDA and CDC claim they don't have sufficient data at the moment to recommend additional doses of Johnson & Johnson vaccine. However, that data will be available soon.

People who have received the Johnson & Johnson vaccine (J&J), will need booster shots. The administration of the J&J vaccine in the U.S. did not start until March 2021. We expect to have more information on J&J over the next few weeks. CDC, NIH, and FDA officials made a prepared statement to the public on August 18 stating that they have all the data necessary to prepare a timely plan for J&J booster shot.

Can I still be infected even after the third shot?

Although no vaccine can be 100% effective, breakthrough cases are usually milder than normal. Although it is possible to get a breakthrough infection after the third shot, it is less likely.

Some immunocompromised patients may not be protected even after the third dose. Liu stressed that, in addition to taking other safety measures such as masking and distancing patients, people who are in close contact with them, such as their family members and caregivers, should also get vaccinated. She says that protecting their closest contacts will create a protective cocoon for immunocompromised patients.

Cherabuddi says that many times, the patients have done everything right. It is not their fault they are being hospitalized. As a nation and as a community, we should do more to protect them against infection.