Pharmacies and medical offices have begun receiving doses of the updated vaccine

DREAMSTIME PHOTO - The Food and Drug Administration and Centers for Disease Control and Prevention recently authorized "bivalent" booster shots from both Pfizer and Moderna that are made to protect people against both the currently dominant omicron variants and the original strain of the coronavirus.

Over the last year and a half, COVID-19 has taken big leaps in its evolution, getting more transmissible and better at evading our immune systems.

Now we're catching up, with a second-generation booster shot that should give humans a fresh advantage.

The Food and Drug Administration and Centers for Disease Control and Prevention recently authorized "bivalent" booster shots from both Pfizer and Moderna that are made to protect people against both the currently dominant omicron variants and the original strain of the coronavirus.

The Oregon Health Authority (OHA) estimates about 2.7 million Oregonians are eligible.

What is it?

An updated vaccine that's been reformulated to target the currently circulating omicron BA.4 and BA.5 variants of COVID-19, along with the parent strain. Like the original, this one is an mRNA vaccine that teaches our cells how to trigger an immune response to the virus.

In Oregon, BA.5 is the overwhelmingly dominant variant circulating now.

The bivalent shots from Moderna, for people 18 and older, and Pfizer, for people 12 and older, are formulated as a booster dose, so they are available only for people who've already received their first two COVID-19 shots. For people 12 and up, the bivalent boosters are now the standard option.

Updating vaccines is not new; flu shots are updated annually to provide better protection.

Who should get it?

In particular, people 65 and older and people with underlying medical conditions should get the new booster to ensure they remain protected against severe disease and death, according to State Epidemiologist Dean Sidelinger

Sidelinger added that the immunity you got from your original COVID-19 vaccines, boosters or infections wane over time, and for those in high-risk groups, waning immunity can mean an increased risk of severe illness.

"Getting a bivalent booster dose now will kind of rev your immune system up," Sidelinger said. "It will keep you out of the hospital, keep you from dying."

Due to the issue of waning immunity, Sidelinger encourages anyone who is eligible, particularly people who have gone many months without a booster or a COVID-19 infection to get the shot. Anyone 12 and older who is at least two months out from their last COVID-19 shot is eligible.

There's an emerging debate over whether boosters in general should be recommended or required of males 12 to 29 years old. HYPERLINK "" Some doctors have made the argument that for young men in particular, the public health benefits of booster doses may not outweigh the potential harms, due to the higher rate of vaccine associated myocarditis in that group.

People who are now eligible for a booster can choose whichever shot they prefer. It doesn't matter which original vaccine series a person previously received.

When should you get it?

According to the CDC, you should get the new booster shot at least two months after your last vaccine dose. If you've had a recent COVID-19 infection, the CDC recommends waiting at least three months from when you first tested positive or felt symptoms, unless there are urgent reasons you need to boost your protection against repeat infection.

Where can you find one?

If you're looking for a bivalent booster now, public health officials say pharmacies are your best bet. A big part of the state's initial supply went to pharmacies.

In the Portland area, Walgreens and CVS locations received the new booster shots, for example, and had appointments available as of Sept. 7.

You can search for a pharmacy in your zip code that's stocking the boosters using the government's online search tool.

The boosters are also available at some OHA walk-up clinics and high-volume vaccination sites. Techtronix in Beaverton, for example, had bivalent boosters available starting Sept. 7. If you'd prefer to get your booster at the place you go to for primary care, most medical providers started receiving their orders of the new boosters from the state last week.

How safe is it?

This spring, Pfizer and Moderna conducted clinical trials on a bivalent vaccine targeting the BA.1 variant, but they shifted their strategy when it became clear those boosters were no longer a good match for the variants that will be circulating this fall.

The FDA and CDC approved the updated bivalent boosters, which target the BA.4 and BA.5 variant, based on "the totality of the available evidence," including several kinds of safety and efficacy data.

That includes safety data from the clinical trials of Pfizer and Moderna's first attempt at an omicron-specific vaccine, efficacy data from animal trials of the current BA.4 and BA.5 formulation of the booster, and the extensive safety record of the original Pfizer and Moderna vaccines, which hundreds of millions of people have received.

According to Sidelinger, the process Moderna and Pfizer used to develop the boosters is similar to the process for annual updates to the flu vaccine.

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