The World Health Organization says that “countries experiencing exceptional epidemiological circumstances may consider delaying for a short period the administration of the second dose as a pragmatic approach to maximising the number of people benefiting from a first dose while vaccine supply continues to increase. WHO’s recommendation at present is that the interval between doses may be extended up to 42 days.” The operative words here are “exceptional epidemiological circumstances,” and “delaying for a short period … up to 42 days.” That’s 42 days instead of the recommended 28 days, not four months.
Now, however, just when we can see real light at the end of the tunnel, some federal and provincial authorities are betting against the manufacturers and many immunologists that their “real world experience,” which in Canada amounts to a few weeks of very limited evidence, warrants risking the entire enterprise. Even if there are indications that the immune response remains good over four months, what might the effect of a delay be in nine months? In 12?
In recommending a delay of up to four months, Dr. Shelley Deeks, vice-chair of the National Advisory Committee on Immunization, says, “We’re the first country, that I’m aware of, that has gone to four months.” Although she acknowledged that no data were available to support the four-month interval, she said, “given that the vaccine effectiveness is sustained and it hasn’t actually decreased at the two month mark, the four month mark is reasonable.” This kind of reasoning is, frankly, as frightening as it is irresponsible. By that logic, why not try a six-month delay? Why not just forget about the second dose entirely, which many will undoubtedly now do?
This content was originally published here.