Monkeypox vaccine: Australia secures 450,000 doses as cases rise

Health Minister Mark Butler announced yesterday that Australia has secured 450,000 doses of the third-generation monkeypox vaccine.

There are now 58 people infected with the virus in Australia. conversation report.

The announcement comes after the Chief Medical Officer declared monkeypox an “epidemic incident of national importance” last week.

This means the federal government can help states and territories. For example, antiviral drugs and vaccines can be made available through national health stockpiles. It also shows the seriousness of the epidemic and the need to control it.

At least 75,000 Australians need to be vaccinated before the outbreak begins to slow, says Dr Nick Medland, sexual health expert, ASHM president and researcher at Kirby Institute I made it

“[The virus]may not be eradicated until 250,000 doses are given to those most in need,” he said.

“From Covid-19 and HIV, we know that our infectious disease response is only effective when clinicians work hand in hand with those most affected.”

The vaccine rollout will begin in New South Wales on Monday, targeting those most at risk of receiving the first 5,500 doses.

Most of the Australian cases are in New South Wales and Victoria, mostly through travel, although some have spread through the community.

Globally, the number of cases rose from a few hundred to more than 23,000 in three months, with the United States overtaking European countries to record the highest number of cases.

The epidemic still spreads mostly in communities of men who have sex with men, with more than 98% of cases occurring in this group.

Overseas, the co-infection rate of sexually transmitted diseases is about 30%, and the HIV infection rate is about 40%. Australia has much lower HIV prevalence, reflecting success in controlling HIV.

What are the new vaccines?

Third-generation non-replicating vaccines are the preferred vaccines for monkeypox. It carries less risk of serious side effects than second-generation vaccines and is safe for people with weakened immune systems.

Australia hadn’t stockpiled these before the epidemic, but the new announcement is a welcome move.

The vaccine Australia just purchased is manufactured by Bavarian Nordic in Denmark. The only other non-replicating vaccine is LC16m8 from Japan, which is in limited supply as production is difficult to scale up.

Monkeypox is closely related to smallpox, and the smallpox vaccine protects against monkeypox and other orthopoxviruses.

The smallpox vaccine is made from the vaccinia virus. First and second generation vaccines replicate in the body, so if someone is immunosuppressed, the vaccinia virus can spread and cause serious illness.

These vaccines cause myocarditis and pericarditis in 1 in 175 vaccinated people and can cause rare serious side effects.

First-generation vaccines such as Dryvax were used to eradicate smallpox until it was declared eradicated in 1980, but because they were manufactured in calf skin, they contained impurities. rice field.

Second-generation vaccines such as ACAM2000 are created and purified using cell culture. However, these are also replicated in the body and have the same side effects.

First- and second-generation vaccines are given as a single injection through a double-pronged needle puncture into the skin. A scar formed at the site, indicating that it worked.

The third-generation vaccine requires two doses, is administered like any other vaccine, and leaves no scars.

The Australian Technical Advisory Group on Immunization (ATAGI), a vaccine advisory body, recommends priority vaccination for:

Contact with high-risk monkeypox in the last 14 days (including men who have had sex with men who have recently had numerous sexual partners or group sex, and men living with HIV)

sex workers, especially those with high-risk clients

Anyone in a high-risk group planning to travel to a country with a significant monkeypox outbreak.

Antiviral drugs against smallpox (and monkeypox) were likewise not stockpiled before the epidemic, but are expected to become available. Antibody therapy) is also available.

This time the trend is different

We don’t know much more about the virus’ genetic alterations, except that it has over 50 mutations. Viruses seem to mutate continuously — and rapidly.

Some of these changes may be responsible for the rapid spread of the virus and new symptoms. The occurrence of a rash around the genitals and anus is much more common in this outbreak than the classic monkeypox symptoms, in which the rash usually appears on the face, hands, and feet.

A study in Cameroon found an asymptomatic infection rate of 6%. Although not a high percentage, it does indicate that asymptomatic infection is possible. A preprint study (not yet reviewed by other scientists) found that three of his 224 men screened had asymptomatic monkeypox. .

None of the three men had been vaccinated against smallpox, although asymptomatic infections can occur in vaccinated individuals. Still, this does not fully explain the global spread of monkeypox.

So far, the epidemic has not spread widely outside of gay and bisexual men, and the death rate is very low. Most of the deaths are children in African countries where monkeypox is endemic. This means that it is present in animal populations in those countries and causes outbreaks when infection spreads from animals to humans and sometimes from humans to humans.

To date, there have been a small number of deaths in non-endemic countries such as Brazil, India and Spain.

Cases in children have occurred in the United States and Europe. Proper outbreak control is important because the risk of severe outcomes and death is much higher in children.

Australia should be able to control it

It is important to prevent the virus from becoming established in animal hosts, which would be a risk if an epidemic were to become very large. The virus’s primary hosts are rodents, but it can host a variety of animals, including monkeys.

If the virus takes hold in Australian animals, we will have to live with it forever, much like Japanese encephalitis, which was not discovered on the mainland until 2022.

It is not yet known whether native Australian animals are susceptible to monkeypox. Since the virus is excreted in the faeces, there is a risk that environmental contamination will introduce the virus into waterways and infect animals.

Australia should be able to leverage its successful HIV response to bring monkeypox under control.

This requires community engagement, appropriate diagnosis, contact tracing, and the use of vaccines as a pre-exposure vaccine prophylaxis for those attending high-risk events and other high-risk populations. And “post-exposure vaccine prophylaxis” that can be taken after contact with an infected person.

This article originally appeared on conversation Republished with permission.

Monkeypox vaccine: Australia secures 450,000 doses as cases rise

Source link Monkeypox vaccine: Australia secures 450,000 doses as cases rise

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