Why is the Covid-19 vaccine rarer than the flu shot?

In a nutshell, there are fewer manufacturers and distributors of the Covid-19 vaccine. It must be frozen at ultra-cold temperatures, making it difficult to ship and store. Complete vaccination requires two shots, compared to one for flu. And because the serum is brand new, healthcare providers need to give extra time to monitor patients for possible adverse reactions.

All of this must be documented to ensure that the rare vaccine is not wasted; allergic reactions are captured; and second doses, which must be administered within a certain period of time, are properly administered.

“The challenge is for state health departments to closely monitor doses while using the weapons,” said Litjen Tan, chief executive of the Immunization Action Coalition, an organization that disseminates information on vaccines in collaboration with the Centers for Disease Control and Prevention. . . “With the flu shot, you get it and you go away.”

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

be planned.

By comparison, at least four large companies make flu shots, which are delivered directly to healthcare providers by three large distributors and several smaller businesses.

Only one distributor, McKesson Corp.

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

“There are pros and cons to a sole distributor,” said Josh Michaud, co-director of global health policy at the Kaiser Family Foundation, a nonprofit that focuses on health issues. ‘It’s easier for the government to work with one company. They do not juggle multiple contracts and touchpoints. ”

As the distribution of the Covid-19 vaccine increases, there will be a strong argument to expand the number of distributors, he said. ‘McKesson is big, but is it capable of reaching into every corner of every state? Others have relationships with doctors’ offices and medical institutions. ”

Influenza vaccine manufacturers also have an advantage.

Because the mechanisms for the production and distribution of influenza vaccine are well established, healthcare providers may order shots that are administered in the fall and winter in January or February. Production begins six to nine months before distribution, which is then completed in phases over a period of about four months. The distribution of this season began in August.

In contrast, the first Covid-19 vaccine was approved by the Food and Drug Administration on December 11 for emergencies and distribution began on December 14. The states learn how much Covid-19 vaccine they will receive about a week in advance. .

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

Flu vaccine can be kept in the refrigerator, while Covid-19 vaccine should be stored at extremely cold temperatures.

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

“We talk cold,” said Dr. Tan said. “It does not mean that it can not be done, but we have to slow down. We need to be more purposeful and considerate. ”

After the vials have been pierced, all doses must be used within six hours – or discarded.

Once someone has been vaccinated, they should be monitored for 15 minutes, or, if they have an allergic reaction, for 30 minutes, to ensure that they do not react badly.

The vaccination is only completed after a second dose has been administered, and the final uptake should take place 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 with no previous resistance to the deadly disease, the goal is to vaccinate as many people as possible.

“With the flu vaccine, about 50%, or maybe a little more, of the U.S. population is vaccinated within a season,” Dr. Michaud said. ‘With the Covid vaccine, the ultimate goal is to reach a level immunity level of vaccination. No one knows exactly what it is, but it is at least 70%. ”

So far, the US is not even close.

Of the 55.9 million doses of Covid-19 distributed as of Thursday, only 33.9 million have been administered, according to the CDC.

These include 27.2 million people, or less than 10% of the population, who received at least one shot, and 6.4 million, or about 2%, who were fully immunized.

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

Meanwhile, enough flu vaccine has been distributed to vaccinate more than 58% of the population, and according to the results of the survey, 53% of all adults got it.

Write to Jo Craven McGinty by [email protected]