Why the Covid-19 vaccine is less common than the flu vaccine

In short, there are fewer manufacturers and distributors of the Covid-19 vaccine. It must be frozen at ultra-cold temperatures, which makes it difficult to ship and store. Complete immunization requires two vaccines, compared to one for the flu. And because the serum is new, healthcare providers need to give extra time to monitor patients for potential side effects.

All of this must be documented to ensure that the rare vaccine is not wasted; allergic reactions are caught; and the secondary doses, which must be administered within a certain time, are executed correctly.

“The challenge is that state health departments need to specifically monitor doses as they go into arms,” ​​said Litjen Tan, strategy director of the Coalition for Action on Immunization, an organization that distributes vaccine information in partnership with the Centers. for Disease Control and Prevention. . “With the flu vaccine, you get it and you go.”

Currently, only Pfizer and Moderna manufacture Covid-19 vaccines available in the US, although versions from other manufacturers, including Johnson & Johnson and AstraZeneca,

are planned.

In comparison, at least four major companies make influenza vaccines, which are delivered directly to health care providers by three major and several smaller distributors.

One distributor, McKesson Body.

, delivers the Moderna Covid-19 vaccine to the federal government. Because the Pfizer vaccine needs to be frozen at more extreme temperatures, the company packs it in special thermal shippers and works directly with FedEx and United Parcel Service to move it.

“There are advantages and disadvantages to having a single distributor,” said Josh Michaud, associate director for global health policy at the Kaiser Family Foundation, a nonprofit organization focused on health issues. “It is easier for the government to work with a single company. It does not juggle more contracts and contact points ”.

As the distribution of Covid-19 vaccine increases, there will be a “strong argument” to expand the number of distributors, he said. “McKesson is great, but is he able to reach every corner of every state? Others have relationships with doctors’ offices and medical units. ”

Manufacturers of influenza vaccines also have an advance.

Because the mechanisms for manufacturing and distributing the flu vaccine are well established, health care providers are able to order photos in January or February, which will be administered in the fall and winter. Production begins six to nine months before distribution, which is then completed in stages over a period of about four months. Distribution of this season began in August.

Instead, the first Covid-19 vaccine was authorized for emergency use by the Food and Drug Administration on December 11 and distribution began on December 14. States are learning how much Covid-19 vaccine they will receive about a week in advance. .

“It’s more of a just-in-time management strategy,” said Crystal Tubbs, associate director of pharmacy at Ohio State University Wexner Medical Center, which administers about 2,000 Covid-19 vaccines a day. “We are told five to seven days in advance how much vaccine we will receive next week. Then we plan meetings. ”

The flu vaccine can be refrigerated, while the Covid-19 vaccine should be stored at extremely cold temperatures.

Moderna vials contain 10 doses of vaccine and must be frozen at minus 4 degrees Fahrenheit. Pfizer vials contain five or six doses and should be frozen at minus 94 degrees Fahrenheit.

“We’re talking about brutal cold,” said Dr. Tan. “This does not mean that it cannot be done, but we must slow down. We need to be more deliberate and more careful. ”

After the vials are perforated, all doses should be used within six hours – or discarded.

Once someone is vaccinated, they should be monitored for 15 minutes or, if they have a history of an allergic reaction, for 30 minutes to make sure they do not react badly.

Immunization is not complete until a second dose is given, and the final vaccine should be given within 21 days for the Pfizer vaccine and within 28 days for the Moderna product.

Because the Covid-19 vaccine is given to a population without previous resistance to the deadly disease, the goal is to inoculate as many people as possible.

“With the flu vaccine, about 50 percent, or maybe a little more, of the U.S. population is vaccinated in a season,” said Dr. Michaud. “With the Covid vaccine, the ultimate goal is to achieve a level of immunity from vaccination. Nobody knows exactly what it is, but at least 70%. ”

So far, the US is not even close.

Of the 55.9 million doses of Covid-19 distributed since Thursday, only 33.9 million were administered, according to the CDC.

This includes 27.2 million people, or less than 10% of the population, who received at least one stroke and 6.4 million, or about 2%, who are completely immunized.

The agency also estimates that 83.1 million people, or about 25% of the country, have been infected with Covid-19, although it is unclear how long their immunity could last.

In the meantime, enough flu vaccine has been distributed to inoculate more than 58% of the population and, according to survey results, 53% of all adults have received it.

Write to Jo Craven McGinty to [email protected]