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In-Depth: Millions of Americans missing second COVID-19 vaccine

CDC data shows missed doses
Posted at 10:04 AM, Apr 29, 2021
and last updated 2021-04-29 13:04:30-04

SAN DIEGO (KGTV) - As millions of Americans line up, drive up, or roll up their sleeves for the COVID-19 vaccine, a small but significant percentage of them aren't getting the complete dose.

CDC data on vaccine completion status through April 9 shows that, among people with sufficient time to get second doses, nearly 8 percent missed their second dose. That's more than twice as many as they reported in March when the number was 3.4%.

"I'm not completely surprised," says Dr. Shira Abeles, the Medical Director of COVID-19 Vaccine Outreach at UC San Diego Health. "We hoped for 100%. We knew we'd never get it... It just means there's more work to do."

The CDC says they expected the number to rise as vaccine eligibility increased, noting that "The groups initially prioritized for COVID-19 vaccination were more likely to have been vaccinated at their worksite (healthcare providers) or residence (long-term care facilities), potentially reducing barriers and increasing adherence to the recommended vaccine schedule."

But, the CDC also urged healthcare providers and local governments to find out if the missed doses were due to access, equity issues, or vaccine hesitancy. They also noted a limitation of the data because it's likely anyone who got their first and second dose at different locations was recorded as a missed dose.

But Dr. Abeles worries that a bad reaction to the first dose or misinformation about protection levels led some to miss or intentionally skip their second dose.

"I believe that there are plenty of people who either decided not to, or, for whatever reason, haven't gotten around to getting that second dose just yet," she says.

Both the Pfizer and Moderna COVID-19 Vaccines are designed to be given in two shots. For Pfizer, the CDC recommends getting the second dose 21 days after the first. For Moderna, the recommendation is 28 days.

But the CDC also says it's okay to get the second dose of either shot as late as 42 days after the first.

No studies show how effective either vaccine can be if people wait any longer than that.

Several studies have shown that one dose of those vaccines offers some immunity level, anywhere from 52-97%, depending on the study.

But the CDC says only two doses offer the most protection, giving people 95% immunity across the board.

Dr. Abeles says people who skipped their second shot should still go get it, even if it's been more than 42 days.

"The whole point of the second dose is a boosting shot," Dr. Abeles says. "The first dose trains your body, but then that second dose really gets your immune system prepared."

To help with vaccine hesitancy or misinformation, she recommends face-to-face conversations and discussions instead of mandates from the government or healthcare providers.

"I think it's really important to ask, "Why haven't you?" And learn the reasons behind it. Because then we can really target and answer those specific questions," says Dr. Abeles.