October is typically the time of the year for the annual flu vaccine. Each year the flu vaccine contains different strains based upon what the expected predominant strain of flu virus will be that particular year. Last year there were two strains of Influenza A virus and two strains of Influenza B virus. This year there are also two strains of each.
One of last year’s Influenza A strains was called A/Victoria H1N1. That same strain is included in this year’s vaccine.
The other strain last year was called A/Cambodia H3N2. That has been replaced this year by A/Darwin H3N2.
The two B strains for this year are B/Victoria and B/Yamagata.
The southern hemisphere has its flu season during its winter period which coincides with summer in the northern hemisphere.
This year they had more cases than in the previous two years. Of those cases 97.5 percent of them were Type A. Of the Type A infections 97.7 percent of them were the A/Darwin H3N2 strain.
That means that if we have the same strain causing this year’s flu season, the vaccine should be protective.
The most recent data for the week ending Sept. 17, 2022 showed 31 documented cases of flu for that week. Twenty of them were caused by H3N2. Another two of them were caused by H1N1. They accounted for 88.6 percent of all flu cases during that period.
The other four cases were Type B. However, they were not tested for which strain of Type B.
As we enter the flu vaccine season, it would appear that the current vaccine is likely to be effective against this year’s major pathogen. There is no guarantee of that. However, so far the best guess seems to be on track.
COVID update- Numbers continue to show little change. Nationally the number of new cases has gone from 395,000 last week to 349,000 this week. Sussex County numbers went from 285 last week to 307 this week.