Bivalent COVID Vaccines: Everything We Know So Far

What are bivalent COVID vaccines? Simply put, these are COVID-19 vaccines that also target Omicron sub variants. 

As of this writing, CDC reports that BA.4.6 and BA.5 accounted for 97% of total COVID-19 infections across the US. 

Last August 31, the FDA gave vaccine-makers Pfizer and Moderna emergency use authorization to begin distributing a ‘bivalent’ COVID-19 vaccine. This is a booster shot that targets the BA.4, BA.5 spike proteins, as well as the original subvariant. 

Pfizer’s bivalent vaccine is currently available for anyone 12 years old and above. Meanwhile, Moderna’s bivalent COVID vaccine has been approved for use by anyone 18 years old and above. 

“The latest vaccines can help restore protection that has waned since previous vaccination and were designed to provide broader protection against newer variants,” said Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention in a statement. 

Similarly, the European Medicines Agency (EMA) approved two updated vaccines, Comirnaty Original/Omicron BA.1 and Spikevax Bivalent Original/Omicron BA.1. They are authorized for use in anyone over the age of 12, with priority use advised for the immunocompromised.

Here is everything we know so far about bivalent COVID-19 vaccines.

How different are the bivalent COVID vaccines from existing vaccines?

The initial COVID-19 vaccines and booster shots have had the same formula since their introduction in late 2020 – long before the inception of the Omicron variant. The updated vaccine still uses the innovative mRNA technology from the original vaccine. However, it has an additional mRNA mixture containing the spike proteins of BA.4 and BA.5 Omicron sub variants.

“We very deliberately picked BA.4 or BA.5,” said Peter Marks, director of the FDA’s Center for Biologics Evaluation and research in a news briefing. “This gives us a variant that is most up-to-date, and most likely looks closer to something that may evolve further in the fall,”

He added that the efficacy of the bivalent vaccine can help prepare better for future variants.

Have studies been made to test the potency of the bivalent COVID vaccines?

As of this writing, no human clinical trials have been done to examine the long-term efficacy of the bivalent COVID vaccines. 

Pfizer and Moderna did conduct human clinical trials and laboratory studies on the INITIAL bivalent vaccine. Studies found that it induced a strong immune response and longer protection against both the original strain and the BA.1 variant. However, the initial bivalent vaccine was rejected by the FDA since it didn’t provide adequate protection against the prevailing Omicron sub variants. 

But with 450 people still dying of COVID-19 each day, health professionals urged vaccine-makers to expedite an updated bivalent COVID vaccine. To speed up the process, the FDA was willing to accept clinical studies on animals (mice) instead of humans. 

The animal study gave positive results. 

“Mice vaccinated with a BA.4/5 bivalent booster had fewer viruses in their lungs than mice given BA.1 boosters,” said Jacqueline Miller, senior VP of Infectious Disease Development at Moderna, during a CDC meeting. 

She added that bivalent COVID vaccines raise antibody levels in both humans and animals.

Are bivalent COVID vaccines safe?

The FDA gave assurances that approved bivalent COVID vaccines were safe. They pointed out that millions have already been inoculated with the original vaccines, upon which the new vaccines are based. Moreover, they asserted that changes in the mRNA sequence in the vaccines do not affect vaccine safety. Health experts also claim that the side effects of the latest vaccines are similar to the original vaccines. 

In fact, Elisha Hall, Clinical Guidelines Lead at CDC, claims that it’s also safe to get other vaccines (flu and monkeypox), the same day you get your bivalent COVID vaccine. However, it is still uncertain whether the new bivalent vaccine can protect the immunized from reinfection and breakthrough infections. And despite health experts urging citizens to get vaccinated, people are still hesitant for various reasons. 

For those who are concerned, it’s worth pointing out that makers of flu vaccines also change the formulation depending on the dominant strain. 

“We don’t usually have too much clinical information when we are thinking about changing influenza vaccines,” said Sarah Long, an infectious diseases pediatrician at Drexel University College of Medicine in Philadelphia. 

Vaccination and regular COVID testing are the most important measures to reduce the spread of COVID-19. Staying unprotected can put you and your loved ones at risk.

Testing for COVID-19 is still important even for those boosted with bivalent COVID vaccines

The FDA approved the new boosters based on animal trials and evidence from previous variant human trials.

Studies are still ongoing regarding the bivalent COVID vaccines, so it’s important to remain vigilant. If you believe you may have been exposed to COVID-19, get tested even if you don’t exhibit symptoms. You might just have an asymptomatic infection. Moreover, it’s highly recommended to get tested when any of the following occur:

• You experience COVID-19 symptoms
• You live with or plan to visit someone who is immunocompromised 
• Someone you know tested positive for COVID-19
• You have plans to attend a large indoor or outdoor gathering

* FDA still recommends REPEAT TESTING for any at-home antigen test to reduce the risks of false negative results. The advice is to conduct up to three COVID-19 tests after your five-day isolation, each 48 hours apart.

Final thoughts

As the COVID-19 virus continues to adapt and mutate, so should our vaccines.

FDA’s recently approved bivalent COVID vaccines are an effective countermeasure in the fight against COVID-19. The new vaccines incorporate the previous mRNA technology with the spike proteins of the BA.4 and BA.5 Omicron sub variants.

Aside from getting vaccinated, it’s important to follow safety measures to reduce the spread of COVID-19. The latest COVID sub variants are known to evade antibodies induced from vaccines or a previous COVID infection. Simple practices such as wearing masks, social distancing, and getting a PCR or antigen test can save lives.  

Luckily, if you want to get tested for COVID-19, there are various options available: 

• You can have one delivered straight to your home
• You can schedule an in-person lab test for the most accurate results

* If you’re in the NYC area, you can even have tests delivered via UBER. 

These testing methods are a far more accurate way to determine whether or not you have been infected with COVID-19. Errors in testing are minimized since all results are thoroughly analyzed in a lab by medical professionals.