Also called B.1.617.2, the delta variant of concern is spreading rapidly. The delta variant is:

• 64% more infectious than alpha COVID-19, another variant
• Present in all 50 U.S. states
• 83% of strains of COVID-19 in the U.S.

The delta variant is hitting unvaccinated communities especially hard. "Nearly all of the hospitalizations and deaths from COVID-19 are regarded as preventable," says medical director of Infection Control and Epidemiology Mark Rupp, MD. "The COVID-19 vaccines are very effective, even against this more transmissible variant."

Vaccines protect against severe outcomes caused by the delta variant

If you're fully vaccinated, you have great protection from the delta variant.

• Pfizer: A U.K. study found that two doses of the Pfizer vaccine had 96% effectiveness against severe COVID-19 disease caused by the delta variant
• Moderna: A Canada study found that the Moderna vaccine also had 96% effectiveness against severe outcomes from delta variant. This study is not yet peer-reviewed
• Johnson & Johnson: A small study found that the Johnson & Johnson vaccine has a strong neutralizing antibody response against the delta variant

Partially vaccinated people are less protected

One study looked at how effective COVID-19 vaccines are against symptomatic disease caused by the delta variant. They found that two doses of the Pfizer vaccine are 88% effective, but just one dose of the Pfizer vaccine was only 33% effective. That means partially vaccinated people in a two-dose series are much less protected.

Don't wait to get vaccinated

If you haven't yet been vaccinated, remember it takes three or four weeks between doses for either mRNA vaccine, and another two weeks after the second dose until you're fully vaccinated. Or, you can get the one-dose Johnson & Johnson vaccine and wait two weeks to become fully vaccinated.

If you're getting Pfizer or Moderna mRNA vaccines, get your second dose on time. If, for whatever reason, you skipped your second dose, you should proceed with the second dose as soon as possible. You do not need to restart the series over.