In June 2016 a PAWS-PATAS transport arrived in Holland. At a Dutch service station, one hour from the first shelter drop-off, it was discovered that two puppies were very ill with bad diarrhea. There were no very young animals on board, all had been fully vaccinated and all had had their last jab more than three weeks before departure. Exit checks were fine.
What followed was a nightmare, having a van full of dogs, none of which could be unloaded at the arranged shelter destinations. We feared the van would have to return to Spain but, after a number of phone calls, help was found: One of our homing shelters would take all young dogs, another homing shelter would take the boarding dogs of the first one and a further contact in Belgium agreed to take the remainder of the dogs temporarily.
Unfortunately, two of the puppies died and one of the shelters in Holland had to close for a lengthy period because of the virus. It was clear that this was not a normal Parvo infection: there were no young puppies on the transport; all had been fully vaccinated; and all had been healthy at exit check.  What we found we had was a new variation of the Parvo virus, first seen in Spain in 2010.
Studies suggested that this was either a new strain of Parvo or a mutation of the existing virus in Spain.  The new strain/variation has been given the name CPV Type 2C.  It has been detected and identified in recent years by CEVAN (Animal Virology Centre) in Argentina. It appears to have replaced the last known variant CPV-2b and was identified via studies on dogs that that had already completed all their normal vaccinations. So far, there is no vaccination against this new strain, and scientists are still amassing sufficient data to produce papers on their findings.
A vaccine company has confirmed that it is aware that fully vaccinated animals can contract Parvo, but they don´t know if CPV 2C is a mutation or a new strain. Unfortunately, each dog has to be tested and samples sent away for analysis (this costs a lot of money, of course). The company also reported that there were many factors involved: the history of the mother and her vaccination status; each dog´s individual immunity system; and so on. It has been a huge problem with breeders who are desperate for answers and a new vaccine.
There is no prevention other than a strict cross-contamination protocol (which is already in place). The following recommendations were received from vets:

1. Only allow older puppies on transports;
2. A fourth vaccination to be added to the schedule of puppies that are in our care at a very young age;
3. There should be no dogs infected with Parvo anywhere in the shelter when a transport is due to take place.

However, even this is considered risky following an episode elsewhere recently where a litter was found to be infected at 6 months of age.
We know that the incubation period for the new variation/strain is 1 month and not 8 to 10 or 14 days, and this is the reason for the "no puppy intake" intake being extended to a month recently. Despite this, the last outbreak we suffered was through a litter taken in at just over a month in advance of the next transport. All signs of Parvo now have to be considered as if we are dealing with the newest variation/strain.
Two Dutch shelters decided that no more Spanish dogs were to be accepted from PAWS-PATAS but, when we advised them of our new protocol, we were subsequently allowed to re-introduce dogs to them. The staff of both shelters worked hard with their Boards to convince them that we have not made any mistakes in our handling of the situation and they have supported us accordingly.  Our Dutch partners have kept a low profile on these latest Parvo incidents on social media, and PAWS-PATAS has not received any criticism as a result. Our good veterinary record over the years, absolute transparency and fast action in an emergency have gained us credit. Dutch shelters have been informed of our new vaccination schedule and we are now sending only older puppies on transports.
Another veterinarian products/vaccines producer in Belgium has offered to monitor events and keep in touch with vets operating on behalf of PAWS-PATAS while the company continues to work on a new vaccine.  Manuel Zapata, an experienced Spanish vet from Murcia has advised that even fully vaccinated adult dogs can die as a result of the new strain(s) of Parvo. He has reported recently that the new virus has reached Murcia and is expected to spread because people think it is not worth vaccinating against Parvo at all. The most recent PAWS-PATAS outbreak is obviously not the "normal" Parvo version: the puppies died quickly as a result of their hearts being affected soon after showing sign of distress.(Tropismo Cardiaco, provoking a cardiac arrest.) This new form of the virus is creating big problems for European breeders.
The following link gives access to more information for those who are interested. It is an article from Argentina, written in Spanish:
https://shar.es/1Jtj5v