While governments, international bodies and the public health community scramble to arrest the COVID-19 virus, now a pandemic, and with states of emergency declared nationwide and in Massachusetts, medical experts are still trying to come up with vaccines that can do a better job against various strains of influenza that have sickened and killed people for many decades.
The experts say the effectiveness rate of flu shots should be at least 90% successful.
But data collected for nearly two decades by the US Center for Disease Control and Prevention show effectiveness rates often hovers between 40 and 50%.
Data from the 2018-2019 flu season, the most recent set of complete information, first published in June, indicated that a flu shot to prevent influenza A, the H3N2 strain, was only 9% effective in preventing onset of the flu, among all age groups.
Among those from 9 to 49 years old, the effectiveness rate was 3%.
Robert Atmar and Wendy Keitel of the Departments of Medicine and Molecular Virology and Microbiology, Baylor College of Medicine in Houston, wrote a paper on this outcome that was published in the Oct. 30 issue of The Journal of Infectious Diseases.
The researchers said “the H3N2 vaccine strain did not match the circulating virus” it was created to combat. Their paper is titled: “Searching for Improved Flu Vaccines—The Time Is Now.”
The researchers said “there was also a low level of circulation of H3N2 viruses similar to the strain contained in the vaccine.”
They wrote that the H3N2 vaccine failure “is not a new phenomenon.”
Atmar and Ketiel wrote: “What can be done to address this dilemma? The simple answer is to make better influenza vaccines. However, this is not an easy task, and the development of improved influenza vaccines has been a goal for decades. In 2018, the National Institute of Allergy and Infectious Diseases announced a strategic plan to develop a universal influenza vaccine.”
“Despite the relatively low protection afforded by vaccination in some seasons, millions of cases of medically attended illness, tens of thousands of hospitalizations, and thousands of deaths have been averted annually,” they wrote.
The overall effectiveness of flu shots last year for all types of influenza, was 29%, the CDC data shows.
During a congressional hearing Wednesday, Robert Ray Redfield Jr., a virologist who is director of the Centers for Disease Control and Prevention, was grilled by Rep. Harley Rouda, D-California, about testing for influenza and the lack of test kit availability for COVID-19.
Their exchange was as follows:
Rep. Rouda: “Without test kits, is it possible that those susceptible to influenza might have been mis-categorized as to what they actually had – quite possible that they actually had COVID-19?”
Dir. Redfield: “The standard practice is the first thing you do is test for influenza. So if they had influenza they would be positive for influenza.”
Rouda: “But only if they were tested. So if they weren’t tested, we don’t know what they had.”
Rouda: “OK, so if somebody dies from influenza, are we doing post-mortem testing to see if it was influenza or whether it was COVID-19?”
Redfield: “There is a surveillance system of death from pneumonia the CDC has. It’s not in every city, every state, every hospital.”
Rouda: “So, we could have people in the United States dying for what appears to be influenza when in fact it could be the coronavirus, COVID-19.”
Redfield: “Some cases have actually been diagnosed that way in the United States today.”