As BA.5 Spreads, Is Now the Time for a Second COVID-19 Booster Shot?

65 plus people getting second booster shot

The new and highly transmissible BA.5 subvariant of omicron has become the dominant strain of the coronavirus in the United States, accounting for just over 80 percent of all new cases as of July 26, according to the Centers for Disease Control and Prevention (CDC).

The mutation is driving a recent surge in COVID-19 cases. Tracking by The New York Times on July 25 shows the average number of infections in the United States rose by an average of 10 percent over the previous two weeks, while hospitalizations climbed by 12 percent and new deaths jumped by 34 percent.

study published June 17 in the journal Nature found that BA.5 and its sister subvariant, BA.4, not only exhibit higher transmissibility than previous omicron versions, but are also better able to evade protections from three doses of COVID-19 vaccines.

The researchers concluded that current “vaccine boosters may not achieve broad-spectrum protection against new omicron variants.” That may explain why so many people who are fully vaccinated and boosted are getting infected, including  President Joe Biden.

Fortunately, vaccines and boosters appear to be effective at keeping severe illness to a minimum.

“Those who are eligible for a second booster ought to get it now — boosting helped protect the President against serious illness,” says William Schaffner, MD, an infectious-disease specialist and a professor of preventive medicine and health policy at the Vanderbilt University School of Medicine in Nashville, Tennessee.

Even though new omicron-targeting boosters are expected by the fall, White House officials have said there’s no reason to wait. They are encouraging everyone ages 5 and up to get a first booster, and people 50 and older to get a first or second booster. They are also urging immunocompromised individuals ages 12 and up to get boosted.

“Vaccines remain our single-most important tool to protect people against serious illness, hospitalizations, and death, and staying up to date is essential as we see BA.5 rise across the country,” said the COVID-19 response coordinator for the White House, Ashish Jha, MD, MPH, at a press briefing on July 12.

No Need to Wait Until Omicron-Targeted Shots Arrive

Dr. Jha stressed that getting vaccinated now will not preclude you from getting an omicron-specific vaccine or booster when distribution likely begins this fall.

Moderna recently revealed new clinical trial data showing that one month after subjects received its new omicron-targeting booster candidate, they produced levels of neutralizing antibodies that were 1.69 times higher than did subjects who received the original booster.

With BA.5 numbers still high, the Biden administration was considering lowering the age for second boosters to include people younger than 50, but federal health officials speaking anonymously to The Washington Post said that the government decided to hold off because Pfizer and Moderna are expected to have omicron-targeting shots ready by early- to mid-September.

Many Americans Are Not Sufficiently Protected

Part of the urgency behind the White House push for boosters is that many Americans remain unboosted. CDC figures show that 48 percent of those who are fully vaccinated have gotten a first booster, and about 30 percent of those 50 and older have gotten a second booster.

“With summer travel season in high gear, kids headed back to school, and an increase in infections and reinfections with BA.5, everyone over 5 should get a booster if it’s been at least five months since their initial series,” says Jennifer Horney, PhD, a professor of epidemiology and a core faculty member at the disaster research center at the University of Delaware in Newark.

Some Groups Are Especially Vulnerable

Although all those eligible for boosters can benefit from the extra dose, these doses may be especially vital for more vulnerable people and those who live with them or provide caregiving.

  • Adults 65 and over Individuals 65 and older account for 16 percent of the U.S. population but 80 percent of COVID-19 deaths, according to Kaiser Family Foundation. “We have seen severe breakthrough infections at a much higher rate among those 65 and older, and if it’s been five or six months since your first booster, it’s likely your protection has waned,” says Dr. Horney.
  • People with chronic illnesses As the CDC reports, individuals with underlying medical conditions such as obesity, diabetes, asthma, chronic lung disease, and sickle cell disease are at increased risk of becoming very sick from COVID-19.
  • Immunosuppressed individuals Public health experts generally agree that people with weakened immune systems can benefit from an additional shot. These individuals may be receiving treatment for cancer, taking immunosuppressive drugs or high-dose corticosteroids, or experiencing decreased kidney function, for example. “People who are immunosuppressed are more apt to get seriously ill because their immune system has difficulty fighting off infections,” says Dr. Schaffner. “They ought to get the second booster because they need all the help they can get.”
  • Caregivers If you are 50 or older and are a caregiver for someone who is severely immunocompromised, you also have a good reason to get a fourth dose of a Pfizer or Moderna vaccine. “You want to create a cocoon of protection around that person,” says Schaffner, “so you’re going to say to yourself, ‘I’m going to go the extra mile in protecting my relative who is living with us and is receiving cancer chemotherapy.’”

Why the CDC Decided to Recommend a Second Booster

The CDC made its decision to recommend second boosters in March based on early evidence suggesting that the second booster (fourth shot) increases protection against severe COVID-19 for people at higher risk of becoming very ill, without posing any safety concerns.

In one of the first investigations of the effectiveness of a second mRNA booster against omicron subvariants, a CDC study in July found that a second booster shot significantly improved effectiveness against widespread variants omicron BA.1 and BA.2/BA.2.12.1.

With the first booster, vaccine effectiveness against these subvariants was only 68 percent and declined to 52 percent after six months. With the second booster, effectiveness climbed to 80 percent within the first six months. Data is not yet available on effectiveness after six months.

SOURCE: https://www.everydayhealth.com/coronavirus/as-ba5-spreads-is-now-the-time-for-a-second-covid-19-booster-shot/

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