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Is The Novavax COVID Vaccine Better Than MRNA Vaccines? What We Know So Far

As the updated COVID vaccines roll out around the country, one more competitor has joined the mix. In early October the U.S. Food and Drug Administration authorized a new booster shot made by the company Novavax. Like the mRNA-based Pfizer and Moderna shots, it targets a SARS-CoV-2 variant, XBB.1.5, which is a descendant of Omicron. It is the first protein vaccine to appear in more than a year, which some public health experts say is encouraging news for people who are hesitant the mRNA vaccines that have been widely used throughout the pandemic.

Scientific American consulted experts on the latest science behind the new shot.

What's different about Novavax's vaccine?

Unlike Moderna's and Pfizer's mRNA vaccines, which contain modified viral genetic material that the body's own cellular machinery uses to make viral proteins that elicit an immune response, Novavax relies on a more traditional approach in which proteins resembling those in SARS-CoV-2 are injected directly into the body. This protein-based method has been used for more than 30 years in other vaccines, such as the hepatitis B vaccine. The company Novavax produces the protein in moth cells, which grow more quickly than mammalian cells.

The Novavax jab also includes a proprietary compound called Matrix-M, which was developed from the bark of Chilean soapbark trees and further stimulates the immune system. Matrix-M is now being integrated into other vaccines, including one for malaria that the World Health Organization approved earlier this month.

What variants does it target?

The new Novavax vaccine was developed for the XBB.1.5 viral variant—the same one targeted by Moderna's and Pfizer's updated shots. None of these are optimized for newer versions of the virus, including the Eris and Pirola variants that became prominent in August and appear better able to escape the immune system than previous mutants. (The FDA selected the XBB.1.5 variant for this fall's boosters in June). That's nothing new, says vaccinologist Gregory Poland of the Mayo Clinic—vaccine companies have been "chasing the tail" of emerging variants throughout the pandemic, he says.

All three vaccine boosters seem to confer at least some protection against the new variants. But one disadvantage of protein vaccines is that it takes much longer for researchers to develop new formulas to protect against new variants, whereas mRNA vaccines can be adapted far more easily.

How effective is it?

Novavax has about the same efficacy as other COVID vaccines, says infectious disease researcher Kirsten Lyke of the University of Maryland. A study published this month found that the Novavax booster was about 55 percent effective at preventing COVID symptoms and 31 percent effective at preventing infection, which is similar to the mRNA vaccines.

Lyke's own July study in the journal npj Vaccines tested whether "mixing and matching" the different COVID vaccine and booster types produced stronger or more durable immunity against the virus. It found that all the boosters led to similar antibody responses regardless of whether a person had initially received an mRNA or protein vaccine. Other evidence published in 2022 suggested that receiving an mRNA booster after a protein vaccine, such as Novavax's original shot or the now-discontinued Johnson and Johnson protein subunit vaccine, might produce the best immunity of all.

According to Lyke's most recent study, the antibodies elicited by the new Novavax booster may have lasted a little longer than those produced after an mRNA vaccine. But Lyke says that's not conclusive: by the time the study began early in 2022, many vaccinated people had recently been infected with Omicron or another dominant variant that's good at avoiding the immune system. The infection gave their body a level of natural immunity that was difficult to distinguish from the vaccine's effects.

Lyke says it is nearly impossible to directly compare different vaccines' efficacy, given that people have had different exposures, infections and combinations of vaccinations. "I just don't think we can run those trials anymore," she says.

What are the side effects?

Compared with mRNA vaccines, the Novavax booster seems to have a lower risk of causing myocarditis or pericarditis—heart conditions that occasionally occur, especially in young men—although it does not have zero risk. It also has fewer side effects, including muscle fatigue and nausea, in the first 48 hours after vaccination. "If people have had a side effect with an mRNA vaccine, I'd say try a protein subunit [vaccine]," Poland says. "The goal is to get you protected."

But it is difficult to draw firm conclusions on the vaccines' comparative safety. "We've got millions of data points for the mRNA vaccine, and we don't have that for Novavax," Poland says. Manufacturing issues prevented the company's immunization against the original COVID variant from being approved until 2022—long after most people who wanted a vaccine had gotten one. The CDC estimates that fewer than 90,000 doses of the original Novavax vaccine were administered, and only a few hundred people have received the booster in clinical trials.

When will Novavax be available for the fall and winter season?

Novavax says the booster is now available in pharmacies and that it has shipped millions of doses to thousands of locations around the country. Like the mRNA vaccines, the Novavax booster is one dose, but the CDC recommends that unvaccinated people receive two doses eight weeks apart.

The rollout of the latest round of boosters—both the mRNA and protein varieties—has lagged despite rising numbers of COVID infections in recent weeks. This has largely been because of confusion around how the vaccines would be paid for after the U.S. Government announced it would no longer pay for all COVID vaccines and instead mandated all insurance companies to cover them for free. Some areas won't have boosters available right away as states continue to navigate insurance and delivery complications. But no matter which vaccine booster becomes available first, Lyke says, the most important thing is to "pick one and get it."

Why Japan Banned MMR Vaccine

by JENNY HOPE, Daily Mail

Japan stopped using the MMR vaccine seven years ago - virtually the only developed nation to turn its back on the jab.

Government health chiefs claim a four-year experiment with it has had serious financial and human costs.

Of the 3,969 medical compensation claims relating to vaccines in the last 30 years, a quarter had been made by those badly affected by the combined measles, mumps and rubella vaccine, they say.

The triple jab was banned in Japan in 1993 after 1.8 million children had been given two types of MMR and a record number developed non-viral meningitis and other adverse reactions.

Official figures show there were three deaths while eight children were left with permanent handicaps ranging from damaged hearing and blindness to loss of control of limbs.

The government reconsidered using MMR in 1999 but decided it was safer to keep the ban and continue using individual vaccines for measles, mumps and rubella.

The British Department of Health said Japan had used a type of MMR which included a strain of mumps vaccine that had particular problems and was discontinued in the UK because of safety concerns.

The Japanese government realised there was a problem with MMR soon after its introduction in April 1989 when vaccination was compulsory. Parents who refused had to pay a small fine.

An analysis of vaccinations over a three-month period showed one in every 900 children was experiencing problems. This was over 2,000 times higher than the expected rate of one child in every 100,000 to 200,000.

The ministry switched to another MMR vaccine in October 1991 but the incidence was still high with one in 1,755 children affected. No separate record has been kept of claims involving autism.

Tests on the spinal fluid of 125 children affected were carried out to see if the vaccine had got into the children's nervous systems. They found one confirmed case and two further suspected cases.

In 1993, after a public outcry fuelled by worries over the flu vaccine, the government dropped the requirement for children to be vaccinated against measles or rubella.

Dr Hiroki Nakatani, director of the Infectious Disease Division at Japan's Ministry of Health and Welfare said that giving individual vaccines cost twice as much as MMR 'but we believe it is worth it'.

In some areas parents have to pay, while in others health authorities foot the bill.

However, he admitted the MMR scare has left its mark. With vaccination rates low, there have been measles outbreaks which have claimed 94 lives in the last five years.

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Should My Son Have The MMR Jab?

The only adverse reaction which would mean that your son could not have the 2nd dose of MMR vaccine is if he had a severe allergic response (anaphylaxis) to the first dose.

Such a reaction involves a swollen mouth and throat, breathing difficulties, shock and sometimes a rash. It occurs in about 1 in 100,000 children after MMR vaccination. I have summarised all serious reactions to MMR below - they are all much rarer than the effects of the natural disease:

Convulsions

Rate after natural disease - 1 in 200Rate after 1st dose of MMR - 1 in 1,000

Meningitis/encephalitis

Rate after natural disease - 1 in 200 to 1 in 5,000

Rate after 1st dose of MMR - 1 in 1000,000

Blood clotting

Rate after natural disease - 1 in 3,000

Rate after 1st dose of MMR - 1 in 24,000

Severe allergic response (anaphylaxis) -

Rate after natural disease - not applicable

Rate after 1st dose of MMR - 1 in 100,000

Deaths

Rate after natural disease - 1 in 8,000 to 1 in 10,000

Rate after 1st dose of MMR - 0

It is much more common for children to have a mild reaction after the MMR jab. Because the MMR vaccine contains viruses that are very similar to those that cause the actual diseases of Measles, Mumps and Rubella, mild symptoms of these disease can occur. This is a sign that the vaccine is working properly and causing an immune response.

Soon after immunisation the injection site may become sore, red or swollen. About ten days after the injection children may experience a very mild form of measles with rash (about 1 in ten), fever (about 1 in 15), loss of appetite and a general feeling of being unwell. More rarely (1 in 50) a child may develop a mild form of mumps with swelling of the glands in the cheek, neck or under the jaw about three weeks after immunisation which only lasts a day or two.

One to three weeks after the immunisation the rubella component may cause pain, stiffness or swelling of one or more joints which goes within about three days. This is very rare in children and occurs more often when adult women are given the vaccine.

You ask if it is likely that the first MMR jab will have done the trick. The vaccine doesn't work in five to ten per cent of children. A second dose of vaccine significantly increases protection. Amongst children who did not respond to the first MMR dose over ninety per cent have a good response to the second dose. Children with low antibody levels after the first dose are boosted.

You say you do not want your son to be vaccinated a second time because of the reaction. Unless your son had an anaphylactic shock reaction as I described above there are no new side effects after the second dose that do not happen after the first dose. In one study there were just as many symptoms in students who had not been vaccinated as in a group who had just had their second dose. This suggests that the reactions were probably not due to the vaccine.

If your son has responded to the vaccine the first time he will not have any problem from being exposed to the viruses again, It's like any of us who are immune meeting someone with the disease - the infection can't get established. If your son did not respond the first time he will still be susceptible to the natural infection and needs the second dose.

You ask about a blood test to see if your son is immune. Firstly the test itself is unpleasant for him. Secondly blood tests are not always 100 per cent accurate and there is a risk that he might not be identified as not being immune, would not receive the MMR and would remain at risk of these diseases

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