Long COVID among breakthrough cases?

Need another reason to mask up? People may get long COVID19 after a breakthrough infection.

While vaccines protect from severe disease, we know the vaccinated can still carry the virus (to some extent, we don’t know this number with Delta) and can, but rarely, display symptoms (i.e. breakthrough cases). The vaccine doesn’t seem to provide 100% “sterilizing immunity”. And this is normal. Many of our vaccines don’t provide this level of protection. For example, our measles vaccine protects us from disease, but we can still carry it if we come in contact with it. This is why a measles outbreak, like at Disneyland, can be very dangerous.

One of the pandemic mysteries is whether the vaccinated (and particularly breakthrough cases) can get long COVID19? Yesterday we got our first look.

The New England Journal of Medicine published a study of breakthrough cases among healthcare workers in Israel. Scientists tested 1,497 healthcare workers from December 19, 2020 to April 28, 2021 at the largest medical center in Israel. (Note this is before Delta).

Of the tested workers, 39 breakthrough cases were detected. All were traced back to unvaccinated index cases (either household members or patients). Among the breakthrough cases…

• Average age was 42 years

• The average time from the second vaccine dose to breakthrough case was 39 days (range: 11-102)

• 1 person was immunocompromised

What did the breakthrough infections look like?

• 67% were mild or asymptomatic. No breakthrough cases were hospitalized

• The most common symptom was coughing (36%), followed by muscle pain (28%), loss of smell or taste (28%), and fever (21%)

• 31% had symptoms lasting more than 14 days

• 19% had symptoms lasting more than 6 weeks (i.e. long COVID). This included loss of smell, cough, fatigue, weakness, difficulty breathing, and/or muscle pain

  • Nine workers (23%) took more than 10 days off from work. One worker had not yet returned after 6 weeks.

Bottom line:

Breakthrough infections with Alpha were rare. However, 1 in 5 breakthrough cases reported long COVID19, regardless of severity of disease. We need a whole lot more data, but this is a really important first look in understanding the burden of breakthroughs.

We know that Delta is less forgiving than Alpha. If you’re not convinced already, it’s time to mask up.

Love, YLE