The consequences of a fall in the vaccination rate can lie dormant for years. A measles outbreak in Wales this year stemmed from opposition to vaccines in the late 1990s. And it has taken 20 years for Japan to feel the implications of dropping the measles, mumps and rubella (MMR) shot.
Japan has a patchy record of administering the rubella vaccine--with boys largely excluded from immunization campaigns--and dropped the MMR shot in 1993 amid safety concerns. The upshot is that many men aged 20 to 40 years old lack protection against rubella. This demographic has been hit hardest by a 2013 rubella outbreak, accounting for 75% of the more than 10,000 cases in Japan up to June 9. There were only 2,392 cases in the whole of 2012, and that marked a sharp rise over the previous two years.
The outbreak is concentrated in cities frequented by business travelers--such as Tokyo--and the Centers for Disease Control and Prevention (CDC) fears this puts U.S. citizens at risk. The CDC has issued a warning advising pregnant women--who face the most severe effects of rubella--to talk to their doctors before visiting Japan. The same warning applies to Poland, which has seen more than 26,000 cases of rubella this year. Fewer U.S. citizens visit Poland, though, so Japan is viewed as the bigger concern, the New York Times reports.
Japan is trying to regain control over rubella by increasing the vaccination rate, but a shortage of MMR shots is expected to hinder efforts, The Japan Times reports. The health ministry fears it could run low on vaccines as soon as August and is prioritizing the immunization of women in response to the anticipated shortage. Ministers reportedly contacted MMR vaccine producers to boost output but were told it would take up to 18 months to ramp up manufacturing. Japan approved a Takeda vaccine for measles and rubella in 2005 and gave the nod to a Kitasato Institute jab two years ago. GlaxoSmithKline ($GSK), Merck ($MRK) and Sanofi ($SNY) all supply MMR vaccines to other markets.