Covid-19 vaccine: Everything you need to know about the Omicron boosters

CNN
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There’s a new kind of Covid-19 shot coming to a pharmacy or clinic near you.

The US Food and Drug Administration and US Centers for Disease Control and Prevention signed off on updated boosters that target the original strain of the coronavirus as well as the Omicron subvariants BA.4 and BA.5. The hope is that these shots will improve protection against the currently circulating viruses that cause Covid-19.

Here’s everything you need to know about the new bivalent boosters and who can get them.

The new bivalent vaccines carry instructions to help our cells make defenses against two strains of the virus that causes Covid-19. The shots direct cells to make antibodies that bind to certain parts of the spike proteins from both the original strain of the SARS-CoV-2 virus and the BA.4 and BA.5 Omicron subvariants, which share an identical spike.

BA.4 and BA.5 are the dominant variants in the United States, where there’s an average of 91,000 new infections each day.

“These are vaccines that are made, manufactured and delivered identically to the Covid mRNA vaccines that most of us have already gotten,” said Dr. Gregory Poland, who leads the vaccine research group at Mayo Clinic in Rochester, Minnesota. “In a sense, you’ve just changed the blueprints.”

Having twice the blueprints doesn’t mean you’re getting twice the dose of active ingredients, though.

“The total mRNA content – the business part of the vaccine – that leads to the immune response is the same amount,” said Dr. William Gruber, senior vice president of vaccine research and development at Pfizer, which makes one of the updated vaccines.

Pfizer’s booster is a 30-microgram dose that contains 15 micrograms of mRNA against the ancestral strain and 15 micrograms against the BA.4 and BA.5 variants. It is authorized for people as young as 12.

Moderna’s bivalent booster is a 50-microgram dose, with 25 micrograms of mRNA designed to fight the ancestral strain of the coronavirus and 25 micrograms of mRNA designed to fight the BA.4 and BA.5 variants. It’s authorized for people 18 and older.

The earlier mRNA shots are still the first two shots a person will get, but they’re no longer authorized for use as boosters in people age 12 and older.

Millions of vaccines are now shipping to tens of thousands of sites across the country. These include community health centers, health departments and pharmacies.

CVS and Walgreens have started offering the shots. Both chains are scheduling appointments online, and say more slots will be added as they get shipments of the vaccines.

The Biden administration expects appointment availability to ramp up over the first several days, with broad availability in a few weeks. People will be able to find locations at Vaccines.gov.

“You’ll start seeing some places start giving some shots in arms over the weekend, but very relatively few because [of the] Labor Day weekend. And my expectation is over next week, or certainly over the next 10 days, you’re going to start seeing these bivalent vaccines become widely available across the country,” Dr. Ashish Jha, who leads the White House Covid-19 Response Team, told CNN.

As with past Covid-19 vaccines, these shots will be available free of charge. But they may be some of the last Covid-19 freebies from the government, which has said it’s going to start commercializing treatments and vaccines this fall.

Americans ages 12 and older are recommended get the new boosters as long as they’ve already had their primary series of vaccines.

Experts say everyone needs one as protection from both vaccination and infection wanes considerably over time and in all age groups.

“I do believe there will be benefit, essentially for everyone, with clearly more benefit for the elderly and those who have underlying conditions,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said on CNN on Friday.

Adults age 18 and older can get either a Pfizer or Moderna shot. Adolescents ages 12 and older can get an updated Pfizer shot.

You should wait two months after your last vaccine dose to get an updated booster.

For those who have recently recovered from a Covid-19 infection, the CDC recommends waiting at least until the illness has passed and a person is no longer contagious. For best results, it may be better to delay a booster for at least three months after symptoms started. Infection itself probably already acted like a booster; studies have shown that people have a relatively low risk of getting sick again for about three months after they recover.

You may not want to wait as long as three months if Covid-19 levels are already high in your community or if you are reduced immune function.

“Myself as an example, I was vaccinated, doubly boosted and infected, and I will be getting the updated BA.4/5 bivalent vaccine within three months of my having gotten infected, exactly the way the FDA has authorized and the CDC has recommended,” Fauci said.

The government is also preparing to launch a campaign that will urge Americans to get their annual flu shot along with an updated Covid-19 booster.

Children ages 5 through 11 can still be boosted with the older, single-strain vaccines.

Vaccine manufacturers are updating boosters for younger children now. Pfizer said it’s retooling its shots for children ages to 5 through 11 and will ask the FDA for authorization of those updated boosters in early October. It’s working with the FDA to update vaccines for children ages 6 months through 4 years.

Until those are ready, the best way to protect babies, toddlers and gradeschoolers is to get eligible family and friends an updated shot.

Yes, but that’s not all. If a health condition or a medication has lowered your immune function, the CDC recommends a two-pronged approach to boost your protection against Covid-19 – vaccination and preventive treatment with a type of passive immunity called Evusheld. Passive immunity is when antibodies are made in a lab and then given by injection or infusion to help people who can’t make enough of this protection on their own.

Evusheld can be taken every six months and is available for immunocompromised people ages 12 and up. It requires a doctors prescription, but the treatment itself is free. The CDC estimates 7 million people may be eligible to take Evusheld, but most haven’t gotten it because they don’t know about it.

If you need Evusheld, you should wait at least two weeks after getting a Covid-19 vaccine to take it. But after a person has taken Evusheld, there’s no waiting period for getting an updated booster.

A recent review of adverse events after mRNA booster vaccinations in adults the United States found that side effects were less common after booster doses than after second doses of the vaccine, and most were mild. About 1 in 8 adults reported a headache, fever or pain after a booster. In children and teens, commonly reported side effects after boosters were pain at the site of the injection, fatigue, headache and muscle aches.

Very rarely, mRNA vaccines can cause myocarditis, or swelling in or around the heart. After more than 80 million booster doses given in the United States, the government safety surveillance systems received 37 verifiable reports of myocarditis. Most of these were in men.

The highest rates of myocarditis in adults were in younger men – ages 18 to 24. For every million booster doses given to men this age, the CDC expects about that about will have myocarditis. For adolescents, the rate is slightly higher but still extremely low: about 11 cases of myocarditis for every million doses.

Dr. Peter Marks, who directs the FDA’s Center for Biologics Evaluation and Research, said that to minimize this risk, officials are directing that the vaccines be given at least two months after a previous dose.

“It seems to be associated when they’re given closer to one another,” he said.

The evidence for these updated vaccines is a bit different than what was behind earlier versions. These are the first Covid-19 vaccines authorized for use in people after being tested only in mice, following much the same process used each year when annual flu shots are updated.

The FDA allowed companies to submit data from animal tests in order to speed these shots to the…