After living with the Covid-19 pandemic for two full years, at the end of March 2022, the Food and Drug Administration (FDA) authorized a fourth Pfizer and Moderna dose for people aged 50 and older to continue the fight against the virus. The Centers for Disease Control and Prevention (CDC) quickly backed the decision, allowing the fourth shot to be administered widely.
According to new research out of Israel, the fourth dose of the Pfizer-BioNTech vaccine for those 50 years of age or above offers a short-term boost of protection against infection, which starts waning after just four weeks. The study also found that effectiveness against infection in the fourth week after the second booster shot was lower than protection mounted after the third vaccine dose. Protection against the Covid-19 virus then drastically falls eight weeks after receiving the fourth shot.
Uncertainty remains for those already protected by two Pfizer-BioNTech vaccines and the first booster as they now become eligible for another booster shot per the CDC’s recent recommendation - all while many communities experience a continued decline in Covid-19 cases. On the other hand, the first rounds of Covid-19 vaccines also became increasingly less effective as newer mutations of the virus have surfaced.
Health officials continue to monitor cases, particularly around the Omicron variant that is causing concerning global increases in infection rates. Updated analysis from the CDC indicates that the highly transmissible BA.2 subvariant of Omicron, known commonly as the “stealth variant,” is now the dominant strain in the United States. According to a large new study, the second Pfizer-BioNTech booster vaccine provides additional short-term protection against these Omicron infections and severe illness among older adults.
Patients 50 years of age or above should speak with their doctor and discuss the appropriateness and the timing of a second booster/fourth Covid-19 vaccine.
Effectiveness: Boosters Work on Covid-19
For those who already received their two Covid-19 mRNA vaccines through Pfizer-BioNTech or Moderna, there is ample data that shows how effective the initial booster vaccine is, especially against the Omicron subvariant and the recent dominant stealth BA.2 strain.
When Omicron’s BA.1 strain was the main variant, the effectiveness of the first two doses of the vaccine against severe disease dropped to 79%, according to a CDC study. Thus far, however, the effectiveness of three doses has remained high at 94%.
CDC data shows that Americans aged 85 years and older account for the largest share of deaths from Covid-19, followed by 75- to 84-year-olds, and then 65- to 74-year-olds. All together, people aged 50 and older account for more than 93% of the roughly 1 million deaths from Covid-19 in the U.S.
Despite increasing evidence that a second booster, or a fourth Covid-19 shot in total, is effective, many questions still remain for those who are eligible for a fourth dose (people who are 50+ years old or immunocompromised), including:
Can I get a booster shot after Covid?
Even if you have had Covid-19, you should still get your vaccine booster once it's safe to do so.
According to the CDC, after a Covid-19 infection, you can get a booster if your symptoms have resolved, you've been isolated for the recommended period of time, and it has been 3 months (90 days) since you received monoclonal antibodies.
Vaccines and boosters continue to train your immune system to protect you against severe disease from future Covid-19 infections.
How long does the Covid booster shot last?
Specifically, researchers found that after a third shot of the Pfizer Covid-19 vaccine, protection against hospitalizations starts out above 95% (two weeks after the shot) and remains around 80% even after four months. By comparison, with only two shots of any vaccine, protection against severe disease declines to 40% after six months.
But, it has also been found that six months after primary vaccination, young, healthy adults retain substantial immunity to SARS-CoV-2 variants causing Covid-19, especially those that were dominant up until November of 2021.
Can I get a Covid booster if I have a cold or the flu?
If you have mild cold or flu-like symptoms, such as a stuffy nose or headache, but test negative for Covid-19, the CDC advises that you can still get your booster to continue maximum protection against the Covid-19 virus.
Can people who received a booster shot still get Covid?
Contracting Covid-19 after you've been vaccinated is still possible. However, having increased immunity - whether from infection or vaccination - significantly lowers your odds of becoming infected.
Can I get a Covid booster shot during IVF?
Yes, there is zero evidence that the Covid-19 booster disrupts fertility treatment, including in vitro fertilization (IVF). In fact, the American Society for Reproductive Medicine (ASRM) strongly encourages you to get the Covid-19 booster shot even while undergoing IVF or other types of fertility treatments.
Eligibility: Who Qualifies for a Booster?
Americans who are 50 years of age or older can get a second Covid-19 booster if it has been at least four months since their last vaccination.
The FDA recently authorized an extra dose of the Pfizer or Moderna vaccine for the +5 age group as well as for certain younger immunocompromised people. The FDA followed up with approval for the Johnson & Johnson vaccine shortly after.
Ultimately, Covid-19 booster vaccines are proving to help prevent those who become infected with the BA.2 variant from ending up in the hospital severely sick, as well as preventing deaths from the virus.
Utilizing Boosters and Covid Testing Together
Two doses of the Covid-19 vaccine provides limited protection against symptomatic disease caused by the variants like Omicron. A booster after the first two vaccinations was shown to substantially increase protection, but that protection wanes over time.
Engaging in regular testing for Covid-19 can be used to monitor and detect prior infection, confirm if a person has produced an immune response following infection, and even monitor antibody vaccine response.
Utilizing IHD’s Covid Neutralizing Antibody (CNAB) Test takes Covid-19 protection to the next level. Regular testing, using IHD’s at-home CNAB test can help you and your healthcare provider make informed decisions and may also help limit the spread of Covid-19 to your family and others in your community by knowing how protected you are against the virus.