America has TWO potential Zika vaccines ready for human trials – but officials admit they won’t be in use for ‘several years’
- One of the vaccines was based on work done on the West Nile virus
- Was never developed because a drug company partner could not be found
- Clinical trials in people may begin by the end of this year
The United States has two potential candidates for a vaccine for the Zika virus and may begin clinical trials in people by the end of this year, but there will not be a widely available vaccine for several years, U.S. officials have admitted .
Dr. Anthony Fauci, director of the National Institute for Allergy and Infectious Disease, said one of the vaccines was based on work done on the West Nile virus.
Fauci said that vaccine was never developed because a drug company partner could not be found, but he did not see this as an issue for Zika.
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An infectious disease expert told Daily Mail Online that a vaccine for the fast-moving Zika virus – which has been linked to birth defects – will not be developed for close to a decade. That’s because, unlike other viruses that have had recent outbreaks, Zika was assumed to be ‘mild’ and no vaccine had been in development
‘We’re already talking to a few companies who are able to partner with us in advanced development,’ he told a news conference.
Dr. Anne Schuchat of the U.S. Centers for Disease Control and Prevention, said there have been 31 cases of Zika infection among U.S. citizens who traveled to areas affected by the virus. So far, there have been no cases of transmission of the virus through mosquitoes in the United States, she said.
In Geneva, the World Health Organization (WHO) said on Thursday that Zika is spreading ‘explosively’ and could affect as many as four million people in the Americas.
It said the mosquito-borne disease had gone from a mild threat to one of alarming proportions and admitted up to four million people could be infected.
The agency will convene an emergency committee of disease experts on Monday.
They said the organisation needed to learn lessons from its handling of the Ebola epidemic where the ‘agency’s failure to act decisively cost thousands of lives’.
The WHO says it has set up measures to fight the spread including surveillance, laboratories for testing, clinical care and vector control – killing off the mosquitoes spreading the infection.
But Dr Amesh Adalja, senior associate at the University of Pittsburgh Medical Center, told dailymail.com that officials shouldn’t expect any fast results from vaccines.
Before the current outbreak – which is linked to a surge in babies being born with abnormally small heads – Zika was not considered to be a public health risk.
Dr Adalja told Daily Mail Online: ‘There wasn’t any vaccine development being undertaken prior to this outbreak in Brazil.
‘It will be quite a while – and this is on the scale of about a decade for a vaccine to be developed usually.’
There is currently no vaccine or treatment for Zika, which is a close cousin of dengue and chikungunya, two viruses that cause mild fever and rash.
Zika virus is common in parts of Africa and South East Asia, but since 2007 there have been various outbreaks outside of the disease’s comfort zone. It spread to South America in 2014, before reaching Mexico and the Caribbean last year. The first US case was reported in Texas at the start of January
Approximately 80 per cent of people who are infected with Zika have no symptoms.
The other 20 per cent experience ‘mild’ symptoms, such as fever, rash, joint pain, and red eyes.
As a result, there weren’t any Zika vaccines in the pipeline, according to Dr Adalja.
But in recent months, the virus has been linked to a rare birth defect called microcephaly – in which a newborn’s head is smaller than normal and the brain may not have developed properly.
The virus has been found in 24 countries in Latin America and the Caribbean.
The World Health Organization has warned it will soon spread to all countries across the Americas, except for Canada and Chile.
Dr Adalja explained that the public incorrectly assumes a vaccine will be available shortly – because of the rapid vaccine that was made available shortly after the Ebola crisis struck.
He said: ‘A lot of people might be thinking that all of the sudden they had an Ebola vaccine.
‘This is different from Ebola – that vaccine had been in development for many years.’
But now that Zika has become a public health concern, researchers are going into overdrive.
First off, scientists will have to do ‘some basic science’ to see if parts of the virus can be presented to the immune system, according to Dr Adalja.
That phase of the research may involve animal studies in the laboratory – and will involve investigating different ways that the immune system may react to the virus.
And once the first step is completed, scientists will next have to determine whether the vaccine is safe or if it has a high burden of side effects.
They will also have to look into if the vaccine triggers any autoimmune reactions.
The virus is spread through the Aedes mosquito (pictured). As a vaccine won’t be available anytime soon, the medical community should focus on wiping out the mosquito that transmits the disease, the expert said
Dr Adalja said: ‘It takes time, and there are a lot of steps where the process can fail, but it seems to me that because of Zika’s ability to affect fetal abnormalities, it will become a priority.’
He noted that the vaccine won’t work just to limit the disease in adults – but also to limit the effect it can have on fetuses.
However, for the time being, there is no cure for Zika.
The doctor said: ‘Once a person is infected, there is nothing that you can do.
‘If a pregnant woman is infected, there is no treatment that can be done to protect the fetus – it either happens or it doesn’t.’
The best way to prevent a fetus from getting infected right now is for pregnant women to avoid travelling to regions that are affected by the virus.
Dr Adalja added: ‘While we wait for a vaccine, people really need to focus the battle on the mosquitoes that are transmitting the virus.’
A developer recently revealed it created a genetically modified mosquito that reduces the number of mosquitoes spreading Zika.
Oxitec, a UK-subsidiary of US synthetic biology company Intrexon, said it developed a self-limiting strain of the Aedes aegypti mosquito.
The male mosquitoes were modified so that their offspring will die before reaching adulthood or being able to reproduce.
The company said it saw strong results in controlling the population of the Aedes vector that carries Zika and also the dengue virus.
WHAT YOU NEED TO KNOW ABOUT ZIKA
WHAT IS ZIKA?
The Zika (ZEE’-ka) virus was first discovered in monkey in Uganda in 1947 – its name comes from the Zika forest where it was first discovered.
It is native mainly to tropical Africa, with outbreaks in Southeast Asia and the Pacific Islands. It appeared in Brazil last year and has since been seen in many Latin American countries and Caribbean islands.
HOW IS IT SPREAD?
It is transmitted through bites from the same kind of mosquitoes that can spread other tropical diseases, like dengue fever, chikungunya and yellow fever.
It is not known to spread from person to person.
Investigators, though, are exploring the possibility that the virus can be passed on through sex – it was found in one man’s semen in Tahiti and there’s been another report of possible spread of the virus through sex.
An Aedes Aegypti mosquito on human skin in a lab in Cali, Colombia. Scientists there are studying the genetics and biology of this mosquito, which transmits the Zika virus
The World Health Organisation says Zika is rapidly spreading in the Americas because it is new to the region and people are not immune to it. Furthermore, the Aedes aegypti mosquito (pictured) that carries it is just extremely widespread
The World Health Organisation says Zika is rapidly spreading in the Americas because it is new to the region, people aren’t immune to it, and the Aedes aegypti mosquito that carries it is just about everywhere – including along the southern United States.
Canada and Chile are the only places without this mosquito.
ARE THERE SYMPTOMS?
Experts think most people infected with Zika virus don’t get sick.
And those that do usually develop mild symptoms – fever, rash, joint pain, and red eyes – which usually last no more than a week.
There is no specific medicine and there hasn’t been a vaccine developed for it, which is the case for some other tropical illnesses that cause periodic outbreaks.
GLAXO CONSIDERING USING VACCINE TECHNOLOGY FOR ZIKA
GlaxoSmithKline Plc is concluding feasibility studies evaluating whether its vaccine technology is suitable for the Zika virus, a spokeswoman has confirmed.
There is no vaccine or treatment for Zika, which typically causes mild fevers and rashes, although about 80 percent of those infected show no symptoms.
‘We’re concluding our feasibility studies as quickly as we can to see if our vaccine technology platforms might be suitable for working on Zika,’ a Glaxo spokeswoman said in an email.
She declined to provide details but added that vaccine development typically takes 10 to 15 years.
WHY IS IT A CONCERN NOW?
In Brazil, there has been mounting evidence linking Zika infection in pregnant women to a rare birth defect called microcephaly, in which a newborn’s head is smaller than normal and the brain may not have developed properly.
Brazilian health officials last October noticed a spike in cases of microcephaly in tandem with the Zika outbreak.
The connection to Zika is still being investigated, and officials note there are many causes of the condition. Nearly 4,000 cases have been recorded.
Meanwhile, doctors have noted increased reports of a nerve condition called Guillain-Barre that can cause paralysis.
But the link to the Zika virus is not clear; other infections can spark the problem, including dengue fever.
CAN THE SPREAD BE STOPPED?
Individuals can protect themselves from mosquito bites by using insect repellents, and wearing long sleeves and long pants – especially during daylight, when the mosquitoes tend to be most active, health officials say.
Eliminating breeding spots and controlling mosquito populations can help prevent the spread of the virus.
HAVE THERE BEEN CASES IN THE US?
Yes, but in tourists. Since 2007 there have been more than two dozen cases diagnosed in the US all travellers who are believed to have caught it overseas.
(Puerto Rico and the U.S. Virgin Islands have each had a recent case that didn’t involve a traveler.)
There is no vaccine or treatment for Zika, which typically causes mild fevers and rashes, although about 80 per cent of those infected show no symptoms
The kind of mosquito that spreads Zika is found along the southern states, so experts think it’s likely the pests may end up spreading the virus there.
But officials also have said Zika infections probably won’t be a big problem in the US for a number of reasons, including the more common use of air conditioning and door and window screens.
Recent U.S. outbreaks of dengue and chikungunya – carried by the same mosquito – suggest any Zika outbreaks may be relatively small, said Dr. Lyle Petersen of the Centers for Disease Control and Prevention.
WHAT ARE THE TRAVEL ADVISORIES?
US health officials recommend that pregnant women should consider postponing trips to 22 destinations. Latin America: Bolivia, Brazil, Colombia, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Panama, Paraguay, Suriname and Venezuela. In the Caribbean: Barbados, Guadeloupe, Haiti, Martinique, St. Martin and Puerto Rico. Also, Cape Verde, off the coast of western Africa; and Samoa in the South Pacific.
In Brazil, most of the mothers who had babies with microcephaly were apparently infected during the first trimester, but there is some evidence the birth defect can occur later in the pregnancy, CDC officials say.
The travel alert applies to women in any stage of pregnancy.
Read more: http://www.dailymail.co.uk/health/article-3421445/America-two-potential-Zika-vaccines-ready-human-trials-officials-admit-WON-T-use-years.html#ixzz3yglQZ5s7
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