Posts Tagged ‘vaccine’

Malaria Vaccine Shows Promise in Children: Worldwide Fight Gaining Ground

Wednesday, November 30th, 2011 by

A multi-year investment of $500 million USD by the Gates Foundation, GlaxoSmithKline and the U.S. government has yielded partial success in the search for a malaria vaccine. A recent report in the Wall Street Journal relays the results of a clinical trial published in the New England Journal of Medicine indicating that three doses of the vaccine can cut the risk of developing malaria in half for African children ages five to seventeen months. Researchers are encouraged to see a vaccine protect against the malaria parasite, but say further work is needed to establish its true efficacy. The Gates Foundation has spent $1.75 billion so far in its quest to eradicate the disease and continues to pursue a parallel approach—a “transmission blocking” vaccine—that is believed to be the key to ultimate success.

The worldwide fight against malaria appears to be gaining ground. According to the World Health Organization, malaria killed 781,000 people in 2009, down 20% from 2000, and an analysis by the University of California, San Francisco indicates that some twenty countries are in the process of eliminating malaria (map below). For those planning to travel to subtropics, The Centers for Disease Control has published an interactive map of malaria risk that is the most detailed and useful I have seen to date.

Share

Tags: , ,
Posted in Malaria, Vaccinations | Comments »

Polio Breaks Out in Tajikistan

Wednesday, May 5th, 2010 by

The World Health Organization (WHO) is reporting that 171 cases of acute flaccid paralysis, the most common sign of acute polio, have been reported in Tajikistan since January.  It appears that all the current cases are coming from the south-west part of the country which borders Afghanistan and Uzbekistan.  Of the 171 cases, 32 have been confirmed wild poliovirus 1 cases; results are pending for the rest.

The government of Tajikistan is planning a three step program to immunize all the children in the area.  If you are traveling to Tajikistan or any other polio-affected area, be sure to follow the WHO’s recommendation for vaccination.  There are two types of vaccine available, inactivated (IPV) and oral (OPV), and travelers headed into or out of an infected-country should receive a full course of the vaccine as described in Chapter six, page 107 of the WHO’s International Travel and Health Guide.

(Thank you for the photo, Olga!)

Share

Tags: , , , ,
Posted in Polio | Comments »

Personal flu history or seasonal vaccine: shields against H1N1?

Monday, August 10th, 2009 by

noflupopsAlthough the CDC report of May 22, 2009 suggests there is no significant immunity to the novel H1N1 virus from the seasonal flu vaccine, scientists are still at a loss to explain why the H1N1 virus appears to affect pregnant women and children more than the elderly- a striking departure from the epidemiology of seasonal flu.  The logical conclusion is that prior exposure and/or immunization to the various strains of the seasonal flu may provide at least a modicum of immunity to the novel influenza virus.

In fact, the results showed that although blood samples from children had no antibodies to the H1N1 virus, samples from adults who had been vaccinated against seasonal flu showed a slight increase in antibodies against the novel influenza strain.  They went on to add that the H1N1 virus shares 72 percent of its protein identity with the seasonal flu viruses, which may be enough to activate the immune system.       

In its recommendations released last week, the CDC also acknowledged that, according to health experts, the elderly “appear to have higher levels of immunity to the virus”, helping justify their decisions that pregnant women and children six months and older be placed at the front of the line to receive the H1N1 vaccinations this fall. 

So here is the bottom line:  Since the U.S. government is estimating that about 120 million swine flu vaccine doses will be available to the public by late October, and over 160 million will be given priority to receive the vaccine, there is a very good chance that 50% of the U.S. population–those who are not young or pregnant– will have limited access to the H1N1 vaccine.  Which makes us wonder: despite the official proclamation of the CDC that the seasonal flu vaccine has no efficacy against the novel influenza, doesn’t common sense dictate that a little bit of protection may be better than nothing? 

We are not here to contradict the CDC, but it would not be surprising to discover later this year or early next, that those who received the seasonal flu vaccine had a lower rate of infection, or became less ill, than those who did not. 

Food for thought.  Your comments welcome.

Share

Tags: ,
Posted in H1N1 (Swine) Flu | Comments »

H1N1 News: WHO Declares Pandemic, Sets No Travel Restrictions

Thursday, June 11th, 2009 by

swineflupicThe World Health Organization has declared the H1N1 outbreak a pandemic but has characterized it as “moderate in severity” and has not recommended any international travel restrictions.  At a press conference this morning, WHO officials noted that the most severe cases are in adults aged 30 to 50 and said their greatest concern is “we don’t know how this virus will behave under conditions typical in the developing world.” In fact, they anticipate a “bleaker picture as the virus spreads to areas with limited resources, poor healthcare and high prevalence of underlying medical problems.”

This declaration sets in motion a coordinated worldwide effort to manage the spread of the virus and to treat those infected.  Details are sketchy but WHO officials say anti-viral drugs have already been sent to “many countries.”  As for a vaccine, the WHO reports that the first doses will be available in September but in very small amounts.  The WHO will be watching the progress of the pandemic in the coming weeks and will make recommendations on which populations (and countries) should be at the head of the line to receive vaccine supplies.

The Healthy Travel Blog will be tracking events as they unfold and highlighting the angles of most concern to international travelers.  Please stay tuned.

Share

Tags: , ,
Posted in H1N1 (Swine) Flu | 1 Comment »

H1N1 (Swine Flu Virus) Vaccine – What are we waiting for?

Wednesday, May 20th, 2009 by

vaccineThe H1N1 virus is no longer front page news, and the World Health Organization (WHO) has not classified the current outbreak as a pandemic despite 40 countries collectively reporting over 10,000 cases, including 79 deaths. Most epidemiologists agree that widespread transmission of H1N1 is inevitable, and that a more virulent strain may emerge in the fall.  This sobering prediction and the 5 to 6 month lead time to produce a vaccine, beg the question: “Why hasn’t development started?”

There are multiple reasons. For one, the conventional flu may pose more of a global threat than this new strain. According to a recent Los Angeles Times article, mass production of a new H1N1 vaccine could sharply curtail the amount of seasonal flu vaccine available because the new vaccine would be made instead. The WHO, in consultation with manufacturers, is responsible for making this decision. It’s a difficult call because seasonal flu kills 250,000 to 500,000 people each year worldwide (36,000 in the U.S.). So going full steam ahead on a novel H1N1 vaccine presumes the swine flu virus would have an even higher mortality rate.

Another consideration is timing the selection of the H1N1 strain used in development. Because the genetic composition of new flu strains is constantly evolving, premature selection of a strain could render a new vaccine ineffective.  Of course, waiting too long might not allow enough time to manufacture a vaccine to prevent a pandemic.

Compounding this dilemma, one of the key variables in producing a new vaccine is how well the virus can be grown in culture.  According to the WHO, disappointing lab results to date indicate that vaccine manufacturers will not be ready to produce a swine flu vaccine until mid-July at the earliest. If this assessment proves true, a vaccine will not be ready until January, 2010–three months into the flu season.

Finally, mass distribution of the vaccine will not take place until it is clear that the evolving H1N1 virus results in significant morbidity and/or mortality this autumn. Once the vaccine begins to be administered, world health officials will vigilantly watch for any incidence of Guillain Barre syndrome, a complication that affected hundreds of recipients following the mass administration of another swine flu vaccine in 1976. The WHO and CDC want to make sure we don’t once again hatch a cure that is worse than the disease.

Share

Tags: , , ,
Posted in H1N1 (Swine) Flu | Comments »