What happens if you miss the second Coronavirus jab?
All approved COVID-19 vaccines, with the exception of the one developed by Johnson & Johnson which is a single-dose vaccine, require that a person takes two doses for optimal effectiveness.
The vaccine doses have intervals ranging from 21 days to 28 days.
The Sinopharm and Sinovac vaccines currently being administered in Zimbabwe have 28 day intervals between shots, while Sputnik V, which has also been approved for use in the country, has a recommended period of up to 8 weeks in between jabs.
India has also changed its recommendation of the interval between its domesticated AstraZeneca vaccine, Covishield, moved from 4-6 weeks to 6-8 weeks. Covaxin, India’s locally developed vaccine that has also been cleared for use in Zimbabwe, has a 28-day gap between inoculations.
The CDC recommends that if one misses their second dose for any reason, they should try to get it as soon as possible.
“Up to 42 days between doses is permissible when a delay is unavoidable,” the CDC says.
The United Kingdom government says if the course is interrupted or delayed, it should be resumed using the same vaccine, but the first dose should not be repeated.
Can you get two different vaccine doses?
Current advice from most health agencies and experts is to stick with one vaccine.
The latest guidance from the CDC is that vaccines are not interchangeable.
“The safety and efficacy of a mixed-product series have not been evaluated. Both doses of the series should be completed with the same product,” the CDC says in guidance updated on March 5, 2021.
Some governments, such as in the UK, make exceptions under certain specific circumstances.
“For individuals who started the schedule and who attend for vaccination at a site where the same vaccine is not available, or if the first product received is unknown, it is reasonable to offer one dose of the locally available product to complete the schedule. This option is preferred if the individual is likely to be at immediate high risk or is considered unlikely to attend again,” the UK says in its COVID-19 Greenbook.
There are currently some studies to examine the effectiveness of a mixed and matched COVID-19 vaccine regimen.
For now, the advice is to keep to two doses of the same vaccine.
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